Dual mode bph6 bph TM F TM R TE R TE F TM F TM R

ASTA now T18 processing without ring 1 June 2011 SLAC Valery Dolgashev, Jim Lewandowski and Stephen Weathersby

T18 sans ring installed. This requires twice the input power to maintain the same gradient as the ring configuration. This test will elucidate the effect of the ring (previous test) on structure performance.

88 Frequency E+10, 200 ns pulsewidth. Vacuum activity mainly on the input side of the structure. 13 breakdowns at this level.Frequency E+10

Status of T18 in resonant ring processing 13 April 2011 SLAC Valery Dolgashev, Jim Lewandowski and Stephen Weathersby

Two rings couple the input and output power of the T18 (18 cells) travelling wave accelerator structure. Reduces the required input power and hopefully enhances the performance of the structure. Also, the ring configuration is thought to reduce the damaging effects of breakdowns by distributing the breakdown power over time.

Pulse shape, 100 ns charging ns flat ring input structure input ring load File: ppm_data_Mar29_2011, trace#: 1200 with time stamp:{29,3,2011,10,29,51,210} PulseLength:1.54 [us] Pulse Heating: [deg. C] structure input pulse heating

Pulse shape, 100 ns charging ns flat ring input structure input ring load File: ppm_data_Apr05_2011, trace#: 1200 with time stamp: {5,4,2011,8,39,44,128} PulseLength: 0.64 [us] Pulse Heating: [deg. C] structure input pulse heating

Pulse shape, 100 ns charging ns flat ring input structure input ring load structure input pulse heating File: ppm_data_Apr12_2011, trace#: 1200 with time stamp:{12,4,2011,8,41,20,757} Max. PulseLength:0.28 [us] Pulse Heating: [deg. C]

Pulse shape, 100 ns charging ns flat ring input structure input ring load structure input pulse heating File: ppm_data_Apr20_2011, trace#: 1200 with time stamp: {20,4,2011,8,22,35,155} PulseLength: 0.12 [us] Pulse Heating: [deg. C]

T18 in resonant ring, last ~180 hours of processing up to end of shift on April 21 st us flat 600 ns flat 250 ns flat 100 ns flat 1.5 us flat 600 ns flat 250 ns flat 100 ns flat 1.5 us flat 600 ns flat 250 ns flat 100 ns flat

Summary of T18 in resonant ring up to end of shift on April 12 th 2011 Valery Dolgashev, Jim Lewandowski and Stephen Weathersby, 13 April ns 1500 ns 600 ns 200 ns400 ns 100 ns 1500 ns 600 ns 200 ns 400 ns 250 ns

Summary of T18 in resonant ring up to end of shift on April 21 st 2011 Valery Dolgashev, Jim Lewandowski and Stephen Weathersby, 26 April ns 1500 ns 600 ns 200 ns400 ns 100 ns 1500 ns 600 ns 200 ns 400 ns 250 ns 100 ns (2 nd experiment) 100 ns (2 nd experiment)