“The WBS 3 Talk” Scope of work: beam physics support for –injector –IR Demo analysis for upgrade guidance –upgrade design and analysis (specification & performance) –system integration

Beam Physics Activities Injector design certification Revision 1.1 driver accelerator design IR Demo operations support, machine studies & analysis

Injector Resurrection of POISSON gun model PARMELA modeling with IR Upgrade parameters –revert to use of sector dipoles –revised injection conditions Exploratory studies –High performance (low emittance/high current) injector design

IR Demo Analysis IR Demo machine studies in progress –Lattice measurements reinitiated

Upgrade Design IR driver accelerator design Revision 1.1 released: –design frozen –details finalized: integrated final optical cavity design, resolved minor mechanical interferences change request for UV compatibility –preliminary trim, corrector, diagnostic configuration established –preliminary component specifications in discussion UV driver accelerator design Revision 1.1 ready for release ECR for Revision 1.1 in submission

Review of Design Issues & Requirements Source/Injector Performance Delivery of appropriate beam to FEL; beam quality preservation –beam internal self-interaction - space charge –beam external self-interaction - CSR –beam environmental interaction - wakefields, HOMs Machine Performance & Energy Recovery –Space charge, ions, BBU, FEL/RF interaction Geometric, schedule constraints –Must meet cost & schedule, fit in vault, avoid interference with Demo ops as long as possible

Why Revision 1.1? – Technical Motivation Revision 1.0 – a “proof of principle design” meeting design requirements, but with practical difficulties: Injection line geometry (rectangular dipoles) and injection matching conditions (smallish waist) did not provide best available source performance Assumed RF gradients unavailable in existing 5-cell modules Layout –precluded direct upgrade to linac based on three 7-cell modules –allowed inadequate space in the end-loops for realistically engineered trim elements No interface with the UV FEL/no solution for UV transport based upon the available component set Assumed presence of 16 m “broadband” (tune-up) near-concentric optical cavity

What is Revision 1.1? – Changes Expunged 16 m optical cavity (high power cavity now near-concentric; tune-up cavity redundant) –8 dipoles eliminated Sector-dipole injection/extraction line geometry; revised beam envelope matching conditions at injection –9 rectangular/1 sector  8 sector (2 types) –improved source performance “Realistic” energy gains: –55 MeV  40 MeV in 5-cell modules –60 MeV  55 MeV (~7/5 * 40 MeV) in 7-cell module

Revision 1.1: Changes (cont.) Improved layout –linac element spacing supporting direct (“drop-in”) upgrade to a full suite of 7-cell modules –adequate spacing between end-loop dipoles for realistic trim components, including octupoles reverse bend angles/pole face rotations slightly altered; excitations unchanged –clearly defined interface with/solution for UV FEL using standard beam-line components GX bend specifications extended to support UV interface –half-field operation implemented (switch out half of coil pack) –aperture increased –Allows straightforward switching to UV beam line GW length/angle altered slightly to allow common use in IR and UV lines (excitation unchanged)

Revision 1.1 Design In Vault

What Next? Move design into engineering (underway)… –Generate specifications –Error sensitivity analysis –Beam physics studies: theoretical design analysis, machine performance, & beam physics studies must be continued: collective effects: space charge, CSR, BBU, environmental wake, ions, HOM power deposition lattice errors, correction/trim algorithms, operational simulations IR Demo studies: –analyze BBU/other collective effects data collected –continue lattice characterization focusing errors aperture limits –emittance/CSR measurements –injector