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June 16, 2009 Working Group plans Goals of the LC DR Working Group: To give a recommendation on the feasibility of a shorter damping ring by comparing the electron cloud build-up and instability for the 6.4km and 3.2km rings with a 6 ns bunch spacing. DONE: March 2010 by ECLOUD’10 then following the CesrTA program: –1) evaluate the electron cloud in the shorter 3.2 km ring with a 3 ns bunch spacing. –2) give our recommendation on electron cloud mitigations. Furthermore starting late 2010, to fully integrate the CesrTA results into the Damping Ring design.
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June 16, 2009
Today:• Updates on Mitigations KEK – Y. Suetsugu• Updates on photoe- estimates by Synrad3D – K. Harkay• CesrTA last run and updates on mitigations – M. Palmer• DR Working Group plans
June 16, 2009
WG Main Deliverables
Recommendation for the reduction of the ILC Positron Damping Ring Circumference
Recommendation for the baseline and alternate solutions for the electron cloud mitigation in various regions of the ILC Positron Damping Ring.
by March 2010
by Late 2010
Characterization of electron cloud at different bunch spacing: 6ns and 3ns by 2010
June 16, 2009
Working Group plans
Goals of the LC DR Working Group:• To give a recommendation on the feasibility of a
shorter damping ring by comparing the electron cloud build-up and instability for the 6.4km and 3.2km rings with a 6 ns bunch spacing. DONE: March 2010
• by ECLOUD’10 then following the CesrTA program:– 1) evaluate the electron cloud in the shorter 3.2
km ring with a 3 ns bunch spacing. – 2) give our recommendation on electron cloud
mitigations.• Furthermore starting late 2010, to fully integrate the
CesrTA results into the Damping Ring design.
June 16, 2009
Build up simulationsWe run simulations for both ring configurations 6km and 3km with 6ns bunch spacing: IPAC’10 paper: WEPE097 paper in preparation, submission to journal
Next:1) In 3km ring, run with 3ns bunch spacing2) fill pattern?! Discussion.3) Then: need to include refined estimate of photoelectron production rate by SYNRAD3D. Kathy, Laura and Gerry are working on estimates for the ILC Damping Ring.
June 16, 2009
Mitigations Table for ILC Damping Ring
DR element % ring Antechamber need
Coating Mitigation Additional Mitigation
DRIFT in STRAIGHT
54 No Solenoid
DRIFT in ARC
33 Downstream of BEND only
Solenoid
BEND 7 Yes
WIGG 3 Yes
QUAD &SEXT
3 Downstream BEND / WIGG
Color code: Green = defined, Red = not yet defined.
Goal is to define mitigations by 2010 or early 2011 as input for ILC TD Phase 2.
June 16, 2009
Mitigations Table for ILC Damping Ring
DR element % ring Antechamber need
Coating Mitigation Additional Mitigation
DRIFT in STRAIGHT
54 No NEG & Carbon
Solenoid Grooves
DRIFT in ARC
33 Downstream of BEND only
NEG Solenoid Grooves
BEND 7 Yes TiN Grooves
WIGG 3 Yes TiN Clearing Electrodes
QUAD &SEXT
3 Downstream BEND / WIGG
TiN Grooves
Color code: Green = defined, Red = not yet defined.
Goal is to define mitigations by 2010 or early 2011 as input for ILC TD Phase 2.
June 16, 2009
Presentation of the Work at ILC Damping Ring Meeting
• The Working Group will present a recommendation for mitigations to a Damping Ring meeting and a decision will be then made for the baseline as well as for alternate solutions.
• The mechanism for the decision remains yet to be defined. Within the damping ring group, a decision could be taken by means of a voting system based on scaling factors (example: mitigation costs, effectiveness, durability, maintenance etc.) to be defined.
June 16, 2009
• A document produced by the Working Group by late 2010 early 2011, including: the research work, the recommendation on mitigations, the recommendation process and a clear set of criteriae that lead to the recommendation.
Report Document on Mitigations and Recommendation for ILC DR
June 16, 2009
Report Document on Mitigations and Recommendation for ILC DR
June 16, 2009
Our presentations posted on web site
ILC Damping Ring Wiki:• https://wiki.lepp.cornell.edu/ilc/bin/view/Public/
DampingRings/
ILC Damping Ring Teleconference page:• https://wiki.lepp.cornell.edu/ilc/bin/view/Public/
DampingRings/TeleConference
June 16, 2009
Link to all our presentations here
June 16, 2009
Past ILC DR WG meetings
June 16, 2009
WebEx meeting
• Proposed time Next meeting:– Wednesday 14 July 2010
June 16, 2009
Blackboard
Messages board
Messages here
