Beamline 12 ProjectBeamline 12 ProjectBeamline 12 ProjectBeamline 12 Project

BL12 In-vacuum Undulator SourceBL12 In-vacuum Undulator SourceAugust 11, 2004August 11, 2004

Andy RingwallAndy Ringwall

BL12 In-vacuum Undulator SourceBL12 In-vacuum Undulator SourceAugust 11, 2004August 11, 2004

Andy RingwallAndy Ringwall

Present Spear3 9S Straight (the East Pit)Present Spear3 9S Straight (the East Pit)

UPBEAM MATCHING CELL

7.33 m

Y

Z, e- beamX

DRIFT SPOOLS

ENTRANCE MASK

SUPPORTS

GATE VALVE

Beamline 9 on other side of wall

Double Waist Lattice and Vertical Beta FunctionDouble Waist Lattice and Vertical Beta Function

““Double waist” (DW) lattice proposed to replace 9S drift straight: two new ID Double waist” (DW) lattice proposed to replace 9S drift straight: two new ID straights and resulting beamlinesstraights and resulting beamlines

DW studies by M. Cornacchia et al.:DW studies by M. Cornacchia et al.: Low vertical beta function at the center of each straight; Low vertical beta function at the center of each straight; ββ = 1.6 m = 1.6 m Z = 1.8 m space for two undulators (1.5 m devices + approx. 0.3 m of transition length)Z = 1.8 m space for two undulators (1.5 m devices + approx. 0.3 m of transition length) Focusing triplet: three quadrupoles, K values: 1.458, -1.99, 1.458Focusing triplet: three quadrupoles, K values: 1.458, -1.99, 1.458 Four symmetric, 5 mrad chicane bends providing 10 mrad beamline separationFour symmetric, 5 mrad chicane bends providing 10 mrad beamline separation Beta function reduced from Beta function reduced from ββ = 9.9 m to 2.5 m in all four Spear3 matching straights = 9.9 m to 2.5 m in all four Spear3 matching straights

5 mrad chicane bend, 4X

e-

,chicane bend uses S3 style corrector

Triplet

This chicane kick is shown toward wall; design kick is away from wall toward Spear center

Symmetric vs. Asymmetric ChicaneSymmetric vs. Asymmetric Chicane

Symmetric, 5 mrad bend chicane requires redesign and removal of the Symmetric, 5 mrad bend chicane requires redesign and removal of the downbeam matching chamber: $$ risks, schedule risks, technical riskdownbeam matching chamber: $$ risks, schedule risks, technical risk

An asymmetric bend chicane (2.0, 4.4, 14.4 & 8.0 mrad) resolves this An asymmetric bend chicane (2.0, 4.4, 14.4 & 8.0 mrad) resolves this problem and preserves 1.5 m of undulator lengthproblem and preserves 1.5 m of undulator length

e-

Undulator radiation, BL12

Undulator radiation, future beamline

Fixed absorber

Replaceable maskExit flange, start beamline frontend

Asymmetric Chicane (Plan View), ComponentsAsymmetric Chicane (Plan View), Components

Beam “bump” studies at BL9 wiggler chamber characterized the Beam “bump” studies at BL9 wiggler chamber characterized the dynamic aperture giving “conservative” and “aggressive” gaps for the dynamic aperture giving “conservative” and “aggressive” gaps for the new undulator; BL9 chamber has a physical aperture of 12 mm and new undulator; BL9 chamber has a physical aperture of 12 mm and vertical vertical ββ = 4.8 = 4.8

Studies show an effective acceptance of 3.152 mm-mrad to 4.926 mm-mradStudies show an effective acceptance of 3.152 mm-mrad to 4.926 mm-mrad Beta scaling (clear aperture :: Beta scaling (clear aperture :: ββ1/21/2)) to the new straights sets the required to the new straights sets the required

minimum gap of in-vacuum device:minimum gap of in-vacuum device: Conservative: Conservative: 6.20 mm, clear aperture6.20 mm, clear aperture Aggressive: Aggressive: 4.96 mm4.96 mm

Assuming .40 (conservative) or .25 (aggressive) space for Cu-Ni sheets, Assuming .40 (conservative) or .25 (aggressive) space for Cu-Ni sheets, used to reduce wall current impedance, results in pole gaps of:used to reduce wall current impedance, results in pole gaps of:

Conservative:Conservative: 7.0 mm = 6.2 + 2 x .407.0 mm = 6.2 + 2 x .40 Aggressive:Aggressive: 5.5 mm = 4.96 + 2 x .255.5 mm = 4.96 + 2 x .25

Preliminary undulator design:Preliminary undulator design: λλuu = 22 mm, 136 pole, Br = 1.05 (Sm-Co 2:17)= 22 mm, 136 pole, Br = 1.05 (Sm-Co 2:17)

Swiss Light Source in-vac undulator: Swiss Light Source in-vac undulator: λλuu = 17, 19 mm, gap = 4.0 mm, length = 2 m = 17, 19 mm, gap = 4.0 mm, length = 2 m

Bo = 1.003 T (aggressive gap, K = 2.06); .75 T (conservative, K = 1.54)Bo = 1.003 T (aggressive gap, K = 2.06); .75 T (conservative, K = 1.54) K = .093 K = .093 λλu u [mm] [mm] BoBo [T] [T]

Undulator name: U22Undulator name: U22

e- Beam Acceptance, Undulator Gape- Beam Acceptance, Undulator Gap

Vertical Flux Density vs. Aperture

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0

Vertical Clear Aperture (mm)

Bo

(k

G)

[at b

ea

m a

xis

]

Conservative pole gap

Aggressive pole gap

U22 Peak Pole Field, Bo, vs. ApertureU22 Peak Pole Field, Bo, vs. Aperture

(5.0 mm, 10 kG)

(6.2 mm, 7.5 kG)

(20.2 mm, 0.88 kG)

Expected Undulator PerformanceExpected Undulator Performance

U22 conservative pole gap (7.0 mm)

1.00E+17

1.00E+18

1.00E+19

0 5000 10000 15000 20000

energy (eV)

bri

ghtn

ess

(ph

oton

s/s*

mm

^2*

mra

d^

2*0.

1%b

p)

n=1

n=3

n=5

n=7

n=9

n=11

Pole gap = 7 mm

Increasin

g g

ap

decreasin

g B

0

2.5X brightness “jump” at n=5 to n=3 crossover

BL 11 wiggler brightness = 3e16

@ 12 keV

Expected Undulator PerformanceExpected Undulator Performance

U22 conservative (7.0 mm) vs. aggressive (5.5 mm) gap

1.00E+17

1.00E+18

1.00E+19

0 5000 10000 15000 20000

energy (eV)

bri

ghtn

ess

(ph

oton

s/s*

mm

^2*

mr^

2*0.

1%b

p)

Pole gap = 5.5 mm

SLS U19 As BuiltSLS U19 As Built