ESRFStatus of In-Vacuum undulators at ESRF

1- Installed IDs

2- In-Vacuum undulators

3-Magnetic design

4- Magnetic measurements

5- Future

ESRF ID group & Technical services

ESRFHistory of ESRF IDs

ESRF IDs

0

10

20

30

40

50

60

70

80

12/8/1991 24/12/1992 8/5/1994 20/9/1995 1/2/1997 16/6/1998 29/10/1999 12/3/2001 25/7/2002 7/12/2003 20/4/2005 2/9/2006

Date

Nu

mb

er

of

seg

men

ts

5

7

9

11

13

15

17

19

21

23

Avera

ge m

in.

Gap

[m

m]

nb of seg.min gap

November 2003: 68 ID segments installed- 5 in-vacuum undulators (8 in January 2004)- 9 wigglers & asymmetric wigglers- 6 helical undulators ≈

ESRFStatus of in-vacuum undulators

SS Period [mm] L [m] Status

ID11 23 1.6 Jan 99ID22 23 2 July 01

ID9 17 2 July 01

ID29 21 2 Dec 02

ID13 18 2 July 02

ID11 22 2 Dec 2003ID30 23 2 Dec 2003ID30 23 2 Dec 2003

- 5 devices in operation: min. gap 6 mm (5 mm for ID11) - 3 devices ready for installation in December 2003

ESRFOperation of installed In-Vacuum IDs

• Low field Integrals (`≈ 20 G.cm ) for all gap settings are confirmed by regular COD measurements => No correction coils.

• Very small (≈ 5.0e-4) tune shift in multi bunches, 16 bunches, Hybrid user operation

• Some small impedance or tune shift effects observed with all in-vacuum undulator closed in high current single bunch (to be investigated with additional devices).

• Gaps under full user control

<10 % lifetime reduction @ gap 5 mm (uniform & 2/3 filling mode)

40

45

50

55

60

65

70

75

0 5 10 15 20gap [mm]

Acceptable for future operation

@ gap 5 mm

ESRFMagnetic Designs

Soft iron pole

Magnet block

6 devices based on P.P.M. technologyPeriods 17, 18, 21 & 23 mm

1 hybrid device constructed- Period 22 mm

Higher peak field than p.p.m≈ 15-20% forGap/period= 0.25-0.3 (6/22)

Development of

dedicated field correctionmethods

Permanent magnet material : Sm2Co17, Br=1.03 - 1.05 T

ESRFMagnetic measurements (1)

1.0

0.8

0.6

0.4

0.2Effe

ctiv

e pe

ak fi

eld

[T]

28242016128Gap [mm]

2.0

1.5

1.0

0.5

Deflection param

eter K

Measured fieldHybrid U22

- Excellent agreement between calculations (RADIA) and measurements (≈ 1%)

- K= 2.14 @ gap 5 mm

20

16

12

8

4

Gai

n [%

]

0.800.700.600.500.400.30Gap/Period

Gain= (Bh-Bp)/Bp

Bh: hybrid effective peak field (n=1)

Bp: P.P.M peak field (≈ n=1)

ESRFMagnetic Measurements (2)

-0.2

-0.1

0.0

0.1

Fiel

d In

t. [G

.m]

3025201510Gap [mm]

Hybrid U22 Hor. Vert.

P.P.M U23

Hor. Vert.

Field integral correction:- more complicated than p.p.m devices but workable

-many improvements identified (design & field processing)

-Ambient field in SR ≠ in ID lab

--> change field integrals vs gap

--> need active correction (steerer)

On axis

-0.8

-0.6

-0.4

-0.2

0.0

0.2

2nd

Fiel

d in

t. [G

m**

2]

3025201510Gap [mm]

Hybrid U22 Hor. Vert.

P.P.M U23

Hor. Vert.

On axis

ESRFMagnetic Measurements (3)

-0.8

-0.4

0.0

0.4

0.8V

ert.

Fiel

d [T

]

2.42.22.01.81.61.41.21.00.80.60.40.20.0Long. position [m]

U22Gap 6mm

-0.8µm

-0.4

0.0

0.4

0.8

Tran

sv. p

ositi

on [µ

m]

2.42.01.61.20.80.40.0Longitudinal position [m]

Hor. Vert

ESRFMagnetic measurements (4)

4x1018

3

2

1

0

Ang

ular

Flu

x [P

hot./

s/0.

1%/m

rad2 ]

100806040200Photon Energy [KeV]

Error free undulator Actual undulatorHybrid undulator

Period 22 mmL=2 mGap 6 mm

2.8

2.6

2.4

2.22.0

1.8

1.6

1.4

R.m

.s. P

hase

Err

or [d

eg.]

302826242220181614121086Gap [mm]

Hybrid U22 (ID11)P.P.M. U23 (ID30)

R.m.s phase error

Phase shimming

E=6 GeV

I=0.2 A

Filament e beam

Correction of phase error:

-Methods for p.p.m. & hybrid are similar

-the results are also similar

ESRFSummary

Hybrid technology for in-vacuum undulators

In- vacuum undulator U22

-higher peak field than p.p.mis confirmed-> 20 % @ gap/period= 0.25

Field integral shimming & phase shimming are accessiblebut can be optimized with:

-modifications on the mechanicaldesign of the magnetic assembly

-implementation of dedicated numerical tools for hybrid devices

--> room for numerous improvements

ESRFESRF In-Vacuum undulators: tomorrow (1)

Permanent magnet devices1- Update hybrid design for in-vacuum undulators

- mechanical parts of magnetic assembly- field processing & numerical simulations

2- Construction of 2 new hybrid devices- U20 (ID9, 2nd in-vacuum device)- U22 (ID6, test undulator)

Purpose of ID6 U22

Evaluation of potential radiation damage on Sm2Co17 material

-operate permanently @ gap 5 mm

-record regularly spectrum on highharmonics (n=9,11) sensitive to radiation damage

ESRFESRF In-Vacuum undulators: tomorrow (2)

Superconducting devices2.5

2.0

1.5

1.0

0.5

0.0

Fiel

d [T

]

20181614121086Period [mm]

Max. Field ComputedNbTi @ 4.2 Deg KGap = 5 mm

Measurement Anka & Accel

R. Rossmanith et al, EPAC2002

In-vacuum Undulator Gap = 5 mm

Rossmanith et al. ANKA/ACCEL PAC03

Higher peak field-smaller period

Test of a prototype at ESRF foreseen

Partial funding by EC under negotiation

• Magnetism– field calculation– Field correction …

• Cryogenic aspects– Heat budget …

• Low vessel pressure when both cold and warm– Baking ..

• Electron Beam Dynamics , routine operation