1. INTRODUCTION The Fermilab High Intensity Neutrino Source (HINS) program has been developing 325 MHz superconducting spoke resonator accelerating cavities since 2006. Two β = 0.22, single-spoke resonator (SSR1) cavities have been fabricated and both bare cavities were tested in the Fermilab Vertical Test Stand. The first cavity, SSR1-01, now dressed with a helium jacket and a prototype tuner, has been tested in conjunction with commissioning the recently completed 325 MHz Superconducting Spoke Cavity Test Facility. Sensitivities to Q disease and externally applied magnetic fields were investigated. Results are compared to the bare cavity results obtained prior to hydrogen degassing and welding into the helium jacket. 325 MHZ SPOKE CAVITY TEST FACILITY The 325 MHz Spoke Cavity Test Facility (SCTF) is located in the Fermilab Meson Detector Building (MDB). Test Facility Cryostat and Cryogenics Systems The cryostat is a 1.44 m OD, 1.1 m inside-length stainless steel vessel with a warm magnetic shield, an 80 K thermal shield, a cavity support system, and a RF input coupler port. It is capable of cooling any of the test configurations to 4.5 K. Cryogenic fluids are provided by the Meson area Cryogenic Test Facility. The helium pressure at the cavity vessel is unregulated, dependent on the pressure drop of the saturated vapour return flow to the refrigerator compressor suction 250 m away. The baseline vessel pressure is approximately 130 kPa and increases when RF power is introduced. The MAWP of the cavity vessel is 170 kPa. This pressure constraint limited the ultimate cooling capacity to 35 W. In the present configuration, cavity cool-down from room temperature to 5 K takes 15 hours. About three hours are required to transit the 150- 70 K Q disease sensitive zone. The SCTF facility offers both a CW 200 W, 325 MHz power source and a pulsed 250 kW, 325 MHz source capable of pulse lengths up to 3 ms at a 1% duty factor. With a high Q ext drive antenna, the 200 W source is sufficient to drive a SSR1 cavity beyond its design field. The pulsed RF source will be used for dynamic Lorentz force cavity detuning tests and power coupler tests. A modern digital low level RF system with a GUI interface controls either power source. The LLRF offers a 20 kHz bandwidth feedback loop for tracking the cavity resonant frequency. The SCTF LLRF and slow controls interface to Fermilab’s ACNET control system for data logging and other standard services. _________________________________________________________________ *Fermilab is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy HINS PROGRAM OUTLOOK The HINS program looks forward to upcoming technical achievements, in particular, 2.5 MeV beam through the RFQ, installation of the SC cavity test cryostat, first results from SC spoke cavity pulsed-power tests, and demonstration of multiple cavities operating under LLRF system control. The prospect of beam accelerated even to 10 MeV through the warm linac is not imminent due to the timeline for designing and procuring cryogenic transfer lines and feed-cans to supply helium for the SC solenoids in that section. Plans are in the works for a temporary beam line using quadrupole focusing and only a few RT-CH cavities to advance the first demonstration of accelerated beam through vector modulator controlled cavities. As Project X efforts proceed, the identity of the HINS program at least will be altered. An evaluation, based on performance, cost and risk, will determine how and if the HINS technologies are incorporated into a Project X Linac design. SUMMARY/CONCLUSION The Fermilab HINS program has made major progress in developing and fabricating components and systems essential to achieving its multiple, ambitious technical goals. Although realization of those goals is yet in the future, HINS remains highly relevant for the influence it can have on technology choices for any future high intensity proton or H- linac. Success in achieving these goals at the earliest possible date is important for the science of accelerators and for positioning the HINS machine as the front- end of a Project X linac. ACKNOWLEDGEMENTS The authors acknowledge the tireless efforts of the entire HINS team who has realized these many achievements and contributed to this poster. Q 0.vs. E acc and x-ray radiation plot for first cool down of the Roark cavity. During the 2 K scan, E acc reaches 33 MV/m !!-SPOKE CAVITY WORLD RECORD-!! and x-rays decrease after jumping through a MP barrier. Right: RFQ frequency (red, 600kHz span), peak power (green, 600kW span), and pulse width (cyan, 4 msec span) vs. time (40 min span). Below: Network analyzer plots of RFQ modes. Red trace is ‘normal’; blue traces are as RFQ slips into run-away state. Scale is 10 db/div and 11 MHz full span. First peak from left is normal accelerating mode at 325 MHz, second peak is higher order quadrupole mode, third and fourth are dipole modes. T ref is RF turn-on. CW Measurements Resonant frequency and pressure dependence Lorentz Force detuning (LFD) coefficient Q 0.vs. Eacc (Q disease ?) Measure force on piezoelectric tuner actuator during cool down Pulsed Measurements Multipacting barriers? Dynamic Lorentz Force detuning Attempt LFD and pressure variation compensation with piezoelectric tuner High power Pulsed Processing of field emitters. Test cryostat and cryogenics transfer lines will be installed this summer. HORIZONTAL TEST CRYOSTAT FOR SPOKE CAVITIES SUPERCONDUCTING SNGLE-SPKE RF CAVITIES PREVIOUS SSR1-01 PERFORMANCE AT VTS Q0 vs. E acc of Bare SSR1-01 in VTS Manifesting Severe Q Disease Prior to Degassing and Dressing. Upper curve at 2.0K, middle curve at 4.4K, lower curve at 4.4K after attempting to induce Q disease symptoms SSR1-01 TESTS AND RESULTS AT SCTF Q 0 vs. E acc and X-ray Activity of SSR1-01, Degassed and Dressed, in SCTF at 4.7 K Before (upper) and after (lower) attempt to induce Q disease symptoms E acc Scan of SSR1-01 with Three X-ray Detectors RFQ power testing began in late 2008. The RFQ has proven able to accept full peak power, ~450 kW without beam, for pulse lengths up to 3 msec. At average power >250W, the structure begins detuning in a run-away fashion. Four 9.5” columns + 3 gutters each 0.66 leaves 2” margins at each edge. Captions 32, text 24 size f Fermilab LINAC10 --- THP031 FIRST HIGH GRADIENT TEST RESULTS OF A DRESSED 325 MHZ SUPERCONDUCTING SINGLE SPOKE RESONATOR AT FERMILAB* R. C. Webber (webber@fnal.gov), T. Khabiboulline, R. Madrak, T. Nicol, L. Ristori, W. Soyars, R. Wagner FNAL*, Batavia, IL 60510, U.S.A. SSR1-01 HISTORY Bare 325 MHz SSR1 β = 0.22 Single-Spoke Cavity SSR1-01 – First Dressed 325 MHz Cavity with Helium Jacket and Prototype Tuner SSR1-01 in SCTF Cryostat with Coils for Magnetic Field Susceptibility Tests SSR1-01 was fabricated to Fermilab specifications by E. Zanon (Schio, Italy). The bare SSR1-01 was cooled down several times and tested at both 4.4 and 2.0 K in the Fermilab VTS. A maximum E acc of ~20 MV/m was achieved in VTS. The cavity exhibited significant Q disease despite the fast, 20-minute, cool down time at VTS through the 150-70 K sensitive region. An explicit test for Q disease at 4.4 K showed that Q 0 dropped by about a factor of eight. SSR1-01 was sent to JLAB for hydrogen degassing (600 °C vacuum bake for 10 hours). The cavity was then tuned at room temperature for the required 4.4 K frequency. The stainless steel helium jacket was welded to the cavity, and a 20-minute flash, BCP and a HPR were performed at the ANL G150 facility. SSR1-01 TESTS AND RESULTS AT SCTF Q 0 of SSR1-01 at Low and High E acc During Period of ~5000 Quenches in Presence of 8-10 G Magnetic Field Degradation of SSR1-01 Q 0 Due to Magnetic Field Captured During Cool Down. (1 A (red) is 2 G field) FUTURE SCTF AND SSR1 PLANS All SSR1-01 tests reported here were done with the 200 W CW RF source driving the cavity though a high, ~1.5e8, Q ext drive antenna. The cavity met or exceeded all expectations for these test conditions. Soon a high power RF input coupler, suitable for Project X application, will be installed on SSR1-01 and high, pulsed power RF tests will ensue at SCTF. While pulsed operation at ~4.7 K is no longer directly relevant to Project X, this will be the first cold test of the cavity and power coupler assembly. Dynamic Lorentz force detuning and compensation using piezo actuators will also be studied. Plans are underway to extend SCTF operation to 2 K in FY11. Similar measurements as reported here will be repeated at 2 K and the study of microphonics and compensation with the fast piezo tuners at that temperature will be of great interest. SSR1-02 and twelve new SSR1 cavities, expected to arrive at Fermilab in 2011, are ultimately destined for testing at SCTF. in VTS