! *** OPTICS=AD_ACCEL-22JAN21 ***

! LCLS2sc linac extension: end of L3 to start of bypass dogleg

! ==============================================================================
! Modification History
! ------------------------------------------------------------------------------
! 05-MAY-2017, M. Woodley
!  * move EXT/DOG boundary so that CCDLU is in DOG (per K. Fant)
!  * remove IPEXTDOG (per K. Fant)
! ------------------------------------------------------------------------------
! 28-NOV-2016, M. Woodley
!  * merge LCLS-II' version 28NOV16 with LCLS2sc version 04NOV16
! ------------------------------------------------------------------------------
! 26-AUG-2016, M. Woodley
!  * remove EXT FODO lattice and replace with direct match from L3 into dogleg
! ------------------------------------------------------------------------------
! 26-MAY-2016, M. Woodley
!  * set TYPE="0.788D11.50" for R56-compensation chicane bends
! 20-APR-2016, M. Woodley
!  * add IPEXTDOG ion pump (defines EXT-DOG boundary)
! ------------------------------------------------------------------------------
! 01-OCT-2015, M. Woodley
!  * add BPMX09 (@0); to be replaced later by RFBX09 (@2)
!  * undefer R56-compensation chicane
!  * scale bend angles of R56-compensation chicane up by 15%
! ------------------------------------------------------------------------------
! 19-JUN-2015, M. Woodley
!  * corrector locations per F. Carrillo
!  * stripline BPM types per M. Carrasco
! ------------------------------------------------------------------------------
! 28-OCT-2014, M. Woodley
!  * lengthen EXT FODO cells by 12 m (57 m to 69 m)
!  * rematch EXT (layout and optics)
!  * add resistive-wall wakefield MARKer (for ELEGANT) per P. Emma
! ------------------------------------------------------------------------------
! 15-OCT-2014, M. Woodley
!  * switch to 45 degree FODO cells
!  * add R56 compensation chicane (steal 2.5 m from space reserved for CM
!    transport)
!  * adjust deferment/deprecation levels
! ------------------------------------------------------------------------------
! 07-AUG-2014, M. Woodley
!  * diagnostics complement per "Electron Beam Diagnostics Systems" PRD
!    (LCLSII-2.7-PR-0170)
!  * EXT FODO cell length increased from 38 m to 57 m ... phase advance per
!    cell reduced to 60 degrees
!  * use QW quadrupoles for FODO lattice ... last two EXT quadrupoles are QEs
!  * decorate device TYPE attributes to indicate non-baseline status
! ------------------------------------------------------------------------------
! 28-MAR-2014, M. Woodley
!  * element names changed to conform to nomenclature PRD
! ------------------------------------------------------------------------------

! ==============================================================================
! QUAD
! ------------------------------------------------------------------------------

  KQX01 :=  0.953807775866
  KQX02 := -1.076629965523

  QX01 : QUAD, TYPE="1.085Q4.31", L=LQE/2, APER=rQE, K1=KQX01
  QX02 : QUAD, TYPE="1.085Q4.31", L=LQE/2, APER=rQE, K1=KQX02

  COMMENT !GL < 106 kG for QEs
    VALUE, Brhof*KQX01*LQE
    VALUE, Brhof*KQX02*LQE
  ENDCOMMENT

! ==============================================================================
! DRIF
! ------------------------------------------------------------------------------

  LLDX := 21.0-2*LQE !21 m particle-free before CCDLU

  DX00 : DRIF, L=5.8
  DX02 : DRIF, L=5.8
  DX01 : DRIF, L=LLDX-DX00[L]-DX02[L]

  DX01a : DRIF, L=0.4-LQE/2
  DX01c : DRIF, L=0.2
  DX01b : DRIF, L=DX01[L]-DX01a[L]-DX01c[L]
  DX02a : DRIF, L=0.31-LQE/2
  DX02b : DRIF, L=DX02[L]-DX02a[L]

! ==============================================================================
! BPMs
! ------------------------------------------------------------------------------

  BPMX01 : MONI, TYPE="Stripline-2"
  BPMX02 : MONI, TYPE="Stripline-2"

  RFBX02 : MONI, TYPE="@2,CavityS-1"

! ==============================================================================
! XCORs
! ------------------------------------------------------------------------------

  XCX01 : HKIC, TYPE="class-4"

! ==============================================================================
! YCORs
! ------------------------------------------------------------------------------

  YCX02 : VKIC, TYPE="class-4"

! ==============================================================================
! BEAMLINE
! ------------------------------------------------------------------------------

  QX01_full : LINE=(QX01,BPMX01,QX01)
  QX02_full : LINE=(QX02,BPMX02,QX02)

  EXT0 : LINE=(BEGEXT,&
    DX00,&
    QX01,QX01,DX01,&
    QX02,QX02,DX02,&
    ENDEXT)

  EXT : LINE=(&
    BEGEXT,&
    DX00,&
    QX01_full,DX01a,XCX01,DX01b,RFBX02,DX01c,&
    QX02_full,DX02a,YCX02,DX02b,&
    ENDEXT)

! ------------------------------------------------------------------------------

  RETURN