Impedance & SEY of grooved Surface Ecloud in Quadpole

Slides:

Advertisements

Similar presentations

Finding Surface Area Step 1: Flatten the 3-D figure A rectangular prism will flatten to 6 rectangles. Depending on the dimensions of the 3-D figure, you.

Advertisements

KEK Update on the status of the electron cloud studies at KEKB Contents Brief review of our studies Updates Clearing electrode Groove structure SEY measurement.

March 22, 2011 Mauro Pivi SLAC ALCPG11 Eugene Oregon March 19-23, 2011 Working Group plans.

Study of a Clearing Electrode at KEKB - First beam test - Y. Suetsugu, H. Fukuma (KEK), M. Pivi, W. Lanfa (SLAC) 2008/3/3-61TLC08 Sendai.

R&D Plan on Clearing Electrode using the KEKB LER Y. Suetsugu and H. Fukuma, KEKB M. Pivi and L. Wang, SLAC at KEK.

KEK Recent results of beam tests on clearing electrode and grooves 2010/1/191ILC DR WebEx Meeting Y. Suetsugu, KEK.

Latest ILC DR wiggler simulations M. Pivi, T. Raubenheimer, L. Wang (SLAC) July, 2005.

First approach to the SuperB Rings M. Biagini, LNF-INFN April 26th, 2006 UK SuperB Meeting, Daresbury.

LEPP, the Cornell University Laboratory for Elementary-Particle Physics, has joined with CHESS to become the Cornell Laboratory for Accelerator-based Sciences.

Electron Clouds at SLAC Johnny Ng ILC Damping Rings Collaboration Meeting March 4, 2009.

Webex Electron Cloud Evaluations for ILC DR Mauro Pivi on behalf of the ILC Electron Cloud Working Group - by Webex - KILC12 – Daegu Korea April 25, 2012.

Updates of Electron Cloud Studies at KEKB Topics in 2008 Measurement of electron density in solenoid and Q field Mitigation using clearing electrode in.

ILC damping ring Workshop, Dec 19, 2007, KEK, L. WANG Ecloud simulation 2007 ILC Damping Rings Mini-Workshop December, 2007 Lanfa Wang, SLAC.

SuperKEKB Vacuum System - for the positron ring - Y. Suetsugu KEKB Vacuum Group Outline Design and production status of key components Beam pipes for arc.

1 Options for low energy spin manipulation Ken Moffeit, SLAC 2009 Linear Collider Workshop of the Americas 29 September to 3 October 2009 K. Moffeit, D.

ILC08 Chicago November 2008 Summary of Recent Results from SLAC M. Pivi, J. Ng, D. Arnett, G. Collet, T. Markiewicz, D. Kharakh, R. Kirby, F. Cooper,

March 23, 2010 CMAD a tracking and e-cloud beam instability parallel code (M.Pivi SLAC) Taking MAD(X) optics file at input, thus tracking the beam in a.

1 CERN 1 Mar E-CLOUD Build-up in Grooved Chambers Marco Venturini Center for Beam Physics, LBNL ECL2 -- CERN, 1-2 March 2007.

Electron cloud in the wigglers of ILC Damping Rings L. Wang SLAC ILC Damping Rings R&D Workshop - ILCDR06 September 26-28, 2006 Cornell University.

Study Plan of Clearing Electrode at KEKB Y. Suetsugu, H. Fukuma (KEK), M. Pivi, W. Lanfa (SLAC) 2007/12/191 ILC DR Mini Work Shop (KEK) Dec.

October 13,2010 WG Meeting Cornell U. Recommendation for Electron Cloud Mitigations in the ILC Damping Ring ILC DR Working Group October 13, 2010 Cornell.

E-cloud studies at LNF T. Demma INFN-LNF. Plan of talk Introduction New feedback system to suppress horizontal coupled-bunch instability. Preliminary.

Electron Cloud Mitigation Studies at CesrTA Joseph Calvey 10/1/2009.

Compare options: simulations recent history Cloud density near (r=1mm) beam (m -3 ) before bunch passage, values are taken at a cloud equilibrium density.

Compare options: simulations recent history Cloud density near (r=1mm) beam (m -3 ) before bunch passage, values are taken at a cloud equilibrium density.

ILC DR Workshop - KEK December, A new resonance in wiggler simulations: Christine Celata Use POSINST code.

Nov 17, 2009 Webex Assessing the 3.2 km Ring feasibility: Simulation parameters for electron cloud Build-up and Instability estimation LC DR Electron Cloud.

Simulation of multipacting thresholds G. Iadarola and A. Romano on behalf of the LIU-SPS e-cloud team LIU SPS scrubbing review, 8 September, 2015.

Recent Electron-Cloud Mitigation Studies at KEK E-cloud mitigation mini-workshop on November at CERN Kyo Shibata (for KEKB Group)

3 rd INSTALLATION: chicane magnetic field tests PEP-II e+ ring 1 st and 2 nd Feb 2008 Electron cloud installation studies at SLAC ILC tests - SLAC Cherrill.

CesrTA Vacuum System Conversion and Operational Experiences Yulin Li for the CesrTA Team Cornell Laboratory for Accelerator-based ScienceS and Education.

Electron cloud in Final Doublet IRENG07) ILC Interaction Region Engineering Design Workshop (IRENG07) September 17-21, 2007, SLAC Lanfa Wang.

ILC GDE - ILCDR08 Cornell 8-11 July 2008 Electron Cloud Mitigation R&D at SLAC M. Pivi, D. Arnett, G. Collet, T. Markiewicz, D. Kharakh, R. Kirby, J. Seeman,

Electron Cloud R&D at SLAC Johnny Ng SLAC DOE HEP Review July 7 – 9, 2008.

Vacuum System S. Guiducci BTR, LNF 8 July RDR - electron damping ring:

R&D GOALS AND MILESTONES TOWARDS A TECHNICAL DESIGN REPORT TDR (2008) First Intnl. Teleconference Ecloud, Impedance/Instabilities - M. Pivi, SLAC 31 October.

Updates of EC Studies at KEKB 1.EC studies at KEKB 2.Recent results 1.Clearing Electrode 2.Groove surface 3.TiN coating 4.Measurement of EC in solenoid.

3 February 2010 ILC Damping Ring electron cloud WG effort Mauro Pivi SLAC on behalf of ILC DR working group on e- cloud ILC DR Webex Meeting Jan 3, 2010.

Electron Cloud in the International Linear Collider ILC Mauro Pivi work performed while at SLAC and the ILC Damping Ring Working Group High.

Recent Studies on Electron Cloud at KEKB 1.EC studies at KEKB 2.Recent results –Clearing Electrode –Groove surface –EC measurement in Q and solenoid field.

LEPP, the Cornell University Laboratory for Elementary-Particle Physics, has joined with CHESS to become the Cornell Laboratory for Accelerator-based Sciences.

1 2 Phy432 Midterm Test: March 4, 2010 Name: Fig. 1 Fig. 2 Fig. 3

International Linear Collider R&D on electron cloud (SLAC)

Update to ECLOUD Calculations for the

Groove Mitigation and Plans

Electron Cloud Effects in SuperB

Using Time-Resolved Retarding Field Analyzer Measurements to Determine the SEY Mitigation Effectiveness of Grooves -- Bonus: first look at last night's.

Impedance & SEY of grooved surface

ILCDR08 10 July 2008 Plan of measuring cloud density in the solenoid field and in the quadrupole field K. Kanazawa (KEK)

Detailed Characterization of Vacuum Chamber Surface Properties Using Measurements of the Time Dependence of Electron Cloud Development Jim Crittenden.

Ecloud in quadrupole & Sextupole

First Results on Electron Cloud Generation and Trapping in a PSR Quadrupole Magnet R. J. Macek, A. A. Browman & L. J. Rybarcyk, 9/26/06 Acknowledgements:

Work In January 2007, we installed 5 chambers in a straight Field Free region of PEP-II Low Energy Ring (LER). Closest bend at ~18 meters upstream: 1 stainless.

Electron Cloud in ilcDR: Update

SuperB General Meeting June , Perugia (Italy)

Agenda Today: CesrTA and SuperKEKB simulations - Ohmi

ILC DR instability simulations

ILC 3.2 km DR design based on FODO lattice (DMC3)

Code Benchmarking and Preliminary RFA Modelling for CesrTA

Impedance of grooved surface

ILC DR Working Group on Collective Effect: Electron Cloud

ILC 3.2 km DR design based on FODO lattice (DMC3)

ILC Damping Ring electron cloud WG effort

Electron Cloud Build-up in ilcDR

Electron Clouds at SLAC

ILC DR instability simulations

Pulsed Sextupole Injection for Beijing Advanced Photon Source

R&D GOALS AND MILESTONES TOWARDS A TECHNICAL DESIGN REPORT TDR (2008)

Fanglei Lin, Yuhong Zhang JLEIC R&D Meeting, March 10, 2016

3.2 km FODO lattice for 10 Hz operation (DMC4)

Presentation transcript:

Impedance & SEY of grooved Surface Ecloud in Quadpole Lanfa Wang, Mauro Pivi SLAC March 26-30, 2010, Beijing International Linear Collider Workshop 2010 LCWS10 and ILC10

Impedance enhancement factor (Code : Finite Element Method, PAC07 THPAS067, L Wang) The total impedance enhancement=  * percentage of grooved surface *percentage chamber length with grooved surface Triangular groove in dipole and wiggler magnets Round Chamber with radius: 30 mm or 23 mm (two types) Width of grooves inside chamber: 25 mm on top and 25 mm on bottom percentage of grooved surface=26.5%(34.6%) Rectangular groove in drift region percentage of grooved surface=100%

Triangular Grooved surface in Magnet(dipole & wiggler)  =80 Groove depth: 1 mm Roundness: 50 um =1.36 (2)  =80 Roundness: 100 um  =1.23 (3)  =80 Groove depth: 2 mm  =1.49 (4)  =80  =1.39 (1) =1.36 (2) =1.23 (3) =1.49 (4) =1.39

Rectangular groove Low impedance with round tips There is a small impedance enhancement factor for a larger t/p (K.Bane and Stupakov slac-pub-11677) p=1.25mm (period) d=2.5mm (depth) t=0.125mm (thickness) p=1.25mm d=2.5mm t=0.25mm p=1.25mm d=3.5mm t=0.125mm Round tips

Mechanism of reduction of SEY using grooved surface Trap the electrons near the surface…… Magnets Drift region (solenoid) (M. Pivi, PAC05) Rectangular Groove without magnetic field

SEY of Triangle Grooved surface (depth: 1 mm ) There is smaller SEY with smaller roundness at tips  =80 Groove depth: 1 mm Roundness: 50 um =1.36 (2)  =80 Groove depth: 1 mm Roundness: 100 um  =1.23

Triangular Groove (depth: 2 mm ) There is smaller SEY for lager size of groove with the same roundness (3)  =80 Groove depth: 2 mm Roundness: 50 um  =1.49 (4)  =80 Groove depth: 2 mm Roundness: 100 um  =1.39

Summary of the effect of Bfield and shape There is a lager SEY in a stronger magnet There is a smaller SEY for larger groove with smaller roundness (a sharper tip is desired in order to reduce SEY!!) SEY with Dipole field=0.3T SEY with Dipole field=1.6T

Rectangular groove (Drift region only) Deeper groove has smaller SEY Shorter shoulder has smaller SEY (5)p=1.25mm (period) d=2.5mm (depth) t=0.125mm (thickness) (6)p=1.25mm d=2.5mm t=0.25mm (7)p=1.25mm d=3.5mm t=0.125mm

Summary Triangular Groove in Dipole Magnets Groove Type Depth 1mm Roundness 50 um Roundness 100 um Depth 2mm Impedance enhancement  1.36 1.23 1.49 1.39 Peak SEY(0=1.6) at B=0.3Tesla 0.77 0.99 0.59 0.78 Peak SEY(0=1.6) at B=1.6 Tesla 0.86 1.18 0.67 0.91 Rectangular Groove in Drift Region Groove Type d=2.5mm t=0.125mm t=0.25mm d=3.5mm Impedance enhancement  1.64 1.42 1.63 Peak SEY(0=1.6) 0.77 0.88 0.7

E-cloud Trapping in Quadrupole Ecloud can be deeply trapped!!! Sigz=15mm Ib=1.3mA BunchSp=14ns K2=0.517T/m R=1.0 SEY=2.0 Emax=276eV (courtesy J. Calvey) cesrta_quad90nb; Build-up of electrons and its decay during the train gap

Slow decay of ecloud during the train gap Evolution of e-cloud during the train gap, t=70ns

Mirror field Trapping in a quadrupole magnet 2D orbit Field lines 3D orbit Orbit of a trapped photoelectron in normal quadrupole magnet during the train gap (field gradient=0.5T/m)