Diagnostics Tests and Studies for SPL cavities Kitty Liao CERN BE-RF-KS First Open Collaboration Meeting on Superconducting Linacs for High Power Proton Beams (SLHiPP-1)

Diagnostics Tests and Studies for SPL cavities I.Introduction II.Second sound studies & tests III.Thermometric system design & development IV.Summary & future work 28/12/2011-9/12/2011

Introduction hot (quench) spot second sound OST octopus 38/12/2011-9/12/2011 Quench spot Second sound wave OSTs (Oscillating Superleak Transducer) welding line at the equator beam   antenna (RF)

Second Sound Studies Motivation: Nb sample quenched at the bottom of a quadrupole resonator  OST didn’t see 2 nd sound. Tube experiment: I, J, U shape – travel of 2 nd sound 8/12/2011-9/12/20114 OST 361 mm

Second Sound Studies IJU tube tests 2 nd sound was seen on all tubes I, J, U amplitude I > J > U input power , 2 nd sound amplitude  heat flux (Power/surface area) , amplitude  (heater 1> heater 2) 8/12/2011-9/12/20115

Second Sound Studies 2 nd sound velocity travels slightly slower in the tube than in a open space  explanation for missing second sound in the quadrupole resonator rods: 8/12/2011-9/12/ small heat flux of the quench spot 2.amplitude smaller than the noise level 3.bendy structure of the rod decrease the amplitude to be seen

SM18 – SPL measurement today! 1. cavity quench 2. quench imitation 8 OSTs, 2 on each rod 4 quench imitation spots equator neck blind-spots 8/12/2011-9/12/20117

8 1.Iris – diodes 2.Equator, main body – carbon Allen-Bradley (100Ω, 1/8W, ΔR/ΔT≈ 758 Ω/K) resistors 3.Kapton foil 100um thick 4.Resolution: around the equator 23 mm max 5.flat area 20 mm ~ 34 mm Design & Development Octopus Thermometric System

8/12/2011-9/12/20119 ResistorsMUXµc boards 1/3 octopus96243 Half cell Complete cavity SM18 -V3

Design & Development Octopus Thermometric System Schematic of octopus Kapton foil layout Connectors evaluation Circuit board evaluation (behind the wall) Circuit schematic (to be checked: 12.Dec)  Kapton foil PCB is completed (without components) to be matched with the cavity: 19.Dec  List of components : request 12. Dec ~  first prototype octopus PCB: Jan 2013  Programming for microprocessor  Labview programme  PCB boards: Feb 2013  First test March /12/2011-9/12/201110

Summary 8/12/2011-9/12/ Second soundOctopus thermometry Second sound studies to be continued for explaining physics and phenomenon in real quench test octopus development under good progress control and should not be delayed due to components request. (supplies please contact me!) quench imitation tests will be done later on in SM18 along with cavity quench test

Acknowledgements Cornell: OST & its knowledge TE-CRG/Cryolab: Johan Bremer, Christoph Balle and their team Dr. Iwashita for useful T-map experience Colleagues of the RF group; [Olivier Brunner,Wolfang Weingaten] 128/12/2011-9/12/2011

Q & A Thank you very much! 138/12/2011-9/12/2011

Back up slides Kitty Liao CERN BE-RF-KS Diagnostics Tests and Studies for SPL cavities

Second sound extra Helium  Lambda point 2.17K  superfluid He 2 fluid model -normal component + superfluid component Normal fluid Bose-Einstein condensate Entropy, viscocity With no entropy, no viscosity 15 Source: R. Donnelly. Physics today st sound: n, s in phase 2 nd sound: n, s out of phase Fluctuation in density, by changes of pressure Fluctuation in density, by changes of temperature 8/12/2011-9/12/2011

Second sound and first sound below the lambda point 16 Source: McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc. 1.First sound- pressure wave 2.Second sound- entropy (temperature) wave 3.Third sound- wave travels in very thin films of helium in which the thickness of the film varies. 4.Fourth sound- pressure wave travels in superfluid helium. When its confined in a porous material. 5.Fifth sound- temperature wave that propagates in helium confined in superleaks. (analogous to second sound) 8/12/2011-9/12/2011