damage limitations to scientific experiments at the...

23
Viktor Lyamayev (European XFEL, Hamburg) Damage to VUV, EUV, and X-ray Optics V Prague,15-16 April 2015 Damage limitations to scientific experiments at the European XFEL

Upload: dangngoc

Post on 29-Mar-2019

215 views

Category:

Documents


0 download

TRANSCRIPT

Viktor Lyamayev (European XFEL, Hamburg)

Damage to VUV, EUV, and X-ray Optics VPrague,15-16 April 2015

Damage limitations to scientific experiments at the European XFEL

Damage limitations to scientific experiments at the European XFEL

2

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

European XFEL layout

Injector at DESY campus

Linear Accelerator1.9 km17.5 GeV

Undulator/Photon Tunnels

Experiment Hallin Schenefeld

Damage limitations to scientific experiments at the European XFEL

3

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

European XFEL

SASE2(= SASE1)

SASE1, λλλλu= 40 mm0.2–0.05 nm SASE3, λλλλu= 68 mm

1.7–0.4 nm

Some specifications

� Photon energy 0.24–24 keV

� Pulse duration ~ 10–100 fs

� Pulse energy few mJ

� Superconducting linac. 17.5 GeV

� 10 Hz (27 000 b/s)

� 5 beamlines / 10 instruments

� Start version with 3 BLs and 6 instruments

Damage limitations to scientific experiments at the European XFEL

4

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

X-ray pulse structure

X-ray pulse structure of the European XFEL

Average power < 90 WPulse train

(1…2700 pulses)

Damage limitations to scientific experiments at the European XFEL

5

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

X-ray pulse structure

X-ray pulse structure of the European XFEL

Power of each pulse train: 3 mJ * 2700 pulses / 0.6 ms = 13 kW !!!

Damage limitations to scientific experiments at the European XFEL

6

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor LyamayevHarald Sinn, Europpean XFEL

Single Particles, Clusters, and Biomolecules (SPB) Instrument

Focusing optics (KB-mirrors)

X-ray beam size 0.1–1 µm

Detectors4 Mp, 4.5 MHz

Sample injectors

Refocusing Be-lenses (CRL)

Beam Stop

Damage limitations to scientific experiments at the European XFEL

7

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

FEM-analysis of the heat load

The main problem is to combine fine meshing of a small interaction volume (e.g. FWHM = 20 µm) with meshing of much bigger absorbing body (e.g. 50×50×50 mm³).

Damage limitations to scientific experiments at the European XFEL

8

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

FEM-analysis of the heat load

Heat load on the B4C absorber of the Beam Stop (3 consecutive pulse-trains):

time, ms

T, d

egre

es

850

70

500

0 100 200

Damage limitations to scientific experiments at the European XFEL

9

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

FEM-analysis of the heat load

Heat load on the B4C absorber of the Beam Stop

Damage limitations to scientific experiments at the European XFEL

10

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

FEM-analysis of the heat loadThermomechanical stresses in B4C absorber of the Beam Stop

X

Y

Z

Damage limitations to scientific experiments at the European XFEL

11

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

FEM-analysis of the heat load

Tensile stress in B4C absorber of the Beam Stop

Damage limitations to scientific experiments at the European XFEL

12

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Alternative materials for the Beam Stop

CVD diamond 70×70×0.3 mm

Damage limitations to scientific experiments at the European XFEL

13

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Alternative materials for the Beam Stop

CVD diamond 70×70×0.3 mm

Damage limitations to scientific experiments at the European XFEL

14

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Alternative materials for the Beam Stop

Tensile stress in the Beam Stop (CVD diamond)

Damage limitations to scientific experiments at the European XFEL

15

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Beam Stop concept

Attenuator (CVD diamondØ80×0.5 mm)

B4C absorber

Aluminium

Steel flange (DN160CF)

x-ray

Damage limitations to scientific experiments at the European XFEL

16

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Beam diagnostics

Damage limitations to scientific experiments at the European XFEL

17

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Beam Stop of the SPB Instrument

Damage limitations to scientific experiments at the European XFEL

18

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor LyamayevHarald Sinn, Europpean XFEL

SPB Instrument

Focusing optics (KB-mirrors)

X-ray beam size 100 nm – 1 µm

Detectors4 Mp, 4.5 MHz

Sample injectors

Refocusing Be-lenses (CRL)

Beam Stop

Damage limitations to scientific experiments at the European XFEL

19

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Heat load on other instrument components

Compound Refractive Lenses (CRL)

Temperature distribution →

Damage limitations to scientific experiments at the European XFEL

20

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Heat load on other instrument components

Limitations of Compound Refractive Lenses

FEM

Analytical(adiabatic)

Damage limitations to scientific experiments at the European XFEL

21

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Thermomechanical stresses in CRL

Stress (along Y-axis) →

D.D.Ryutov, Thermal stresses in the reflective x-ray optics for the LCLS, Rev.Sci.Instrum. 74, 3722 (2003):

� stresses shouldn’t exceed yield strength (for metals)

� otherwise cycling at 10 Hz will lead to cracking

Damage limitations to scientific experiments at the European XFEL

22

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Thermomechanical stresses in CRL

At heat load leading to T~300 °C compressive stress exceeds yield strength of Be by several times!:

Damage limitations to scientific experiments at the European XFEL

23

Damage to VUV, EUV, and X-ray Optics V 15-16 April 2015Viktor Lyamayev

Summary

� X-ray optics and other components of the instruments (CRL, windows, Beam Stop) can potentially limit the science

� Based on comprehensive FEM-simulations optimized Beam Stop design was developed that can withstand full pulse train (2700 pulses)

� Some components show limitation also due to thermomechanical stresses

� 10 Hz cycling should also be taken into account for definition of permissible stresses