DR Interface to Sources and RTML Mark Palmer GDE August 10, 2011 FNAL Meeting Global Design Effort

DR Layout (BTR version) August 10, 2011 FNAL Meeting Global Design Effort

ELTR Block Diagram (Ewan’s Section A) Electron Injection (reverse for e- extraction) H-bend and horizontal dispersion suppressor section (10s of meters) RDR treaty point Transport line Positron Extraction (reverse for e+ injection) H dispersion suppresion (10s of meters) RDR treaty point Vertical elevator (V-bend a full-wave section a opposite V-bend, 10s, possibly man 10s, of meters) Merging section (length depends on single element kick) Vertical dispersion suppressor section (10s of meters) Reverse arrows for PLTR region V E+ Pulsed & DC Separators E- E+ E- H bend x 2? V E+ August 10, 2011 FNAL Meeting Global Design Effort

DR Injection-Extraction Lines RDR picture Concept based on lines created by I. Reichel for RDR, which include Extraction Dispersion control section Extraction angle plus 1 bend result in transition into tunnel ~30m from septum location Injection Same basic concept in reverse DO NOT handle any vertical adjustments! August 10, 2011 FNAL Meeting Global Design Effort

Reorganization for Post-RDR Straight DR elements reorganized to put all Inj/Ext in one straight with the Central Region re-design No direct impact on these lines Beams should exit tunnel approximately 30 m from the septa Consistent with present ELTR/PLTR layout at few meter level (item to fine tune for January) RDR picture August 10, 2011 FNAL Meeting Global Design Effort

DR Layout (BTR version) Beam lines at ~3.75 m from axis of DR straight with final angle of 243 mrad (13.9°). Location ~30 m “outboard” of inj/ext septa August 10, 2011 FNAL Meeting Global Design Effort

Implications Initial horizontal dispersion correction complete Should keep this to avoid coupling into vertical emittance due to errors Thus vertical “elevator” is effectively in the central region tunnels, NOT part the ELTR/PLTR August 10, 2011 FNAL Meeting Global Design Effort

Vertical Elevator Section Comments 10mrad a ~100m length (1mrad a ~1km!) Hesitate to go with larger kick due to the magnitude of the vertical dispersion created with reasonable strength quads To what precision can we null this vertical dispersion? Pulsed elements for merger (or splitter) 10mrad scale should be fine for slow pulsed elements (ie, inject/extract positron rings one after the other). Fill pattern discussions have led to the tentative conclusion that we likely need to support alternating bunch extraction from the rings to flexibly meet any of the possible ML bunch spacing requirements!! Alternating bunches from the two rings will require a ~3MHz AC element (or elements). What kick magnitude can we assume per unit? What technology. Stability specification directly impacts level at which vertical dispersion is nulled. August 10, 2011 FNAL Meeting Global Design Effort

Vertical Elevator Section (cont’d) Comments (cont’d) Dispersion suppression elements Will this need a pulsed dispersion correction of some sort??? Do we need to measure/monitor the vertical emittance at the end to adequately correct? Allowing a dispersion wave to propagate sounds like a VERY bad idea to me. August 10, 2011 FNAL Meeting Global Design Effort

Needs Lattice designer to lay out the vertical “escalator” Explore expected level of dispersion correction versus escalator length with realistic errors. Pass these numbers to the Low Emittance Transport group to evaluate impact of residual dispersion wave. Who??? Needed immediately Could we target a report for a joint session at Granada? Immediate review of pulsed element options for splitter and merger operation Contact multiple pulsed magnet experts Request attendance at Granada for joint session? At least will need a report Target an escalator configuration down-select at Granada? Then document for DESY meeting. August 10, 2011 FNAL Meeting Global Design Effort