1. 2.1GHz cavity without cell-to-cell coupling slots – 1.875” beam pipe Binping Xiao Aug 20 2015

2. Cavity overview No coupling slots between cells. Beam pipe aperture: cell to cell & end cell 1.875” Dimensions (cavity radius, FPC slot height, nose cones etc) are fine tuned. A = 1.875”A

3. Center cell (beta=1) h [mm]Rd [mm]f [GHz]Rsh [ohm]R/Q [ohm]QE-bound f [GHz]fh-fe[MHz] 157.2542.11072.436E+06115.07621168.32.0499460.76 256.73322.11072.460E+06118.514207592.0565554.15 2.556.44552.11072.466E+06120.17520520.12.0597150.99 356.14332.11072.462E+06121.70320233.12.0627347.97 3.555.82782.11072.458E+06123.185199542.0656245.08 455.50032.11072.446E+06124.54519642.22.0683842.32 554.8152.11072.411E+06126.93618993.22.073537.2

4. End cell aperture:23.8125radius in mm h2.5mm he0mm ∆L [mm]10(beta=1) r7 [mm]Rd [mm]f [GHz]Rsh [ohm] R/Q [ohm]Q 256.24592.11072.715E+06120.83722467.9 3.556.29812.11072.702E+06120.00922516.3 556.35792.110682.686E+06119.07622561.1 756.44442.11072.662E+06117.71322613.4 r7 blending

5. 3-cell Center cell h = 2.5 mm, cell radius: 55.98 mm End cell h = 0 mm with 2 mm blending, cell radius: 54.26 mm Fundamental mode: 2.11035 GHz, 6.69 MΩ shunt impedance, power on cavity 9349.1 W. Modes separation: 2.0812 GHz π/3 mode (+++), 2.0990 GHz 2π/3 mode (+0-), 2.1105 GHz π mode (+-+).

6. Tuner Lt [mm]f [GHz]R/Q [ohm]QQextQtuner Rsh [Mohm]QLPcavity [W]Ptuner [W] 02.11035314.108521283219892.25E+066.685171210815.19349.188.3 -62.10926312.285521516254998.59E+066.719134811669.49301.823.3 -32.10964313.30921457240744.37E+066.722671211345.19296.945.7 32.11151315.091520982191541.21E+066.611249910013.29453.6164.0 62.11326314.019520511162157.16E+056.4408549055.99703.7277.9

7. RF loss 1 2 5 6 7 9 8 11 10 12 13 14,15 17 16 3 4 6 5 14 15 R/Q [ohm]314.0455 Voltage [V]250000 MaterialQPower [W] standing wave power [W] 12.35E+0684.522105 25.00E+073.982943715.93177 34.83E+044119.3001 48.81E+042258.0529 53.08E+05645.81953 61.61E+06123.62762 71.52E+0713.09400352.37601 86.90E+072.884787911.53915 96.89E+072.889730611.55892 105.69E+073.498931913.99573 116.88E+072.89065411.56262 126.99E+072.847964311.39186 131.08E+051848.9014 141.73E+090.11516450.460658 153.61E+080.550682.20272 165.46E+073.643909314.57564 171.55E+081.28256595.130264 total power9117.905

8. And more Alumina window RF loss: 5 Watt (1.25 Watt for travelling wave) with 250 kV. Fixed tuner 3/8” dia, 5mm insertion, frequency increases 0.32 MHz. To compensate the possible Q-degradation brought by surface roughness or brazing. We choose FPC stub 50mm away from the bottom of the flat area on the "V" waveguide, assuming the cavity is 1cm in thickness, we can use 2.75" flange with 1.625" clearance, and 1.5" bolt with 1" dia thread and 10mm insertion. FPC stub position [mm]QextQFPCtuner No21989na 50142942.71E+08

9. Summary For the 2.1 GHz warm RF system: 3-cell cylindrical cavity with nose cones and without coupling slots is designed, and is optimized on shunt impedance. A vacuum pump will be attached to the cavity using a Tee on one of the beam pipe. Cavity is fine tuned for field flatness. Cavity performance at different tuners’ penetrations is evaluated. To do list: Error analysis, HOM modes up to 5 GHz, Pickup coupler.