David Martin High Precision Beamline Alignment at the ESRF IWAA, Grenoble 3-7 October 2016

Transcription

1 David Martin High Precision Beamline Alignment at the ESRF IWAA, Grenoble 3-7 October 2016

2 OVERVIEW The ESRF has just completed the Phase I Upgrade programme. The Phase I Upgrade programme was centered on the construction of a new generation of X-ray instruments and beamlines. 19 of the 30 public beamlines have been completely reconstructed or undergone major refurbishment. Part of this programme included the construction of 8000 m 2 of new experimental hall premises with critical temperature and mechanical stability specifications. Page 2

3 OVERVIEW The Phase II Upgrade - Extremely Bright Source (EBS) - aims to dramatically increase the X-ray source brightness by decreasing the machine horizontal emittance. To do this, the ESRF has chosen to redesign the machine lattice by significantly increasing the number of bending magnets. This new design requires removing the existing machine and replacing it with a new one. This will be done between now and 2020 with the bulk of the assembly and installation scheduled for 2018 to Page 3

4 OVERVIEW We will concentrate on the successful Phase I Upgrade Beamline (UPBL) construction and installation programme: Centering on two specific example beamlines: UPBL7 ID32, and UPBL4 ID16 And discussing several techniques that were used to align the beamline equipment to the required tolerances. Following this Flora Yakhou-Harris (ID32) and Peter Cloetens (ID16A NiNa) will discuss alignment issues and science on their respective beamlines. Page 4

5 THE ESRF The linear accelerator (linac) accelerates the electrons from rest mass to 100 MeV The booster accelerates the electrons from 100MeV to 6GeV The storage ring keeps the electrons circulating at 6GeV for many hours The 6GeV electrons produce synchrotron radiation in a tangential direction to the beam travel A ESRF is composed of two main elements: A particle accelerator that generates synchrotron radiation, and Beamline(s) that use the synchrotron radiation generated by the accelerator to study matter. Page 5

6 NANO PROBE At the ESRF p=150 m and q=0.05 m so q/p= theoretical probe size ~10 nm The size of the focused x-ray probe spot depends on: the source size, the distance between the source and the focusing optics p, and the working distance between optics and the experimental sample q. Page 6

7 THE SCALE OF THINGS AND THE IMPORTANCE OF ALIGNMENT 70 to 180 m 1 mm e- 0.1 mm A crystal is placed on the end of the pin with a stream of cool air coming in from the right. The X-ray beam arrives from the silver pipe and the camera images the crystal Photographer-captures-amazing-crystal-structures-objects-reveals-created.html Page 7

8 THE ESRF SURVEY NETWORKS Z XY and Z XY DiNi 12 Electronic Level 0.3 mm for 1 km 2 way levelling Leica Viva GNSS GS15 receiver 3 mm ppm post processing and long observations AT401/402 Laser Tracker Angles ± 5 μm + 6 μm/m Distance ±10 μm ASME B MPE Page 8

9 THE STORAGE RING NETWORK 30 µm 20 µm e- Instrument stations Page 9

10 EX2 NETWORK Page 10

11 EX2 NETWORK UNCERTAINTY 30 µm 20 µm Page 11

12 ID32 NETWORK Page 12

13 ID32 THE PROBLEM Page 13

14 ID32 OPTICAL ELEMENTS Page 14

15 ID32 HORIZONTAL DOUBLE MIRROR PARALLELISM Side Top Double Mirror Page 15

16 ID32 HORIZONTAL DOUBLE MIRROR PARALLELISM Page 16

17 ID32 HORIZONTAL DOUBLE MIRROR PARALLELISM AND ALIGNMENT Page 17

18 ID32 HORIZONTAL DOUBLE MIRROR PARALLELISM AND ALIGNMENT Page 18

19 ID32 VERTICAL DOUBLE MIRROR PARALLELISM Page 19

20 ID32 VERTICAL DOUBLE MIRROR PARALLELISM Page 20

21 ID32 MONOCHROMATOR Page 21

22 ID32 MONOCHROMATOR Page 22

23 ID16 MONO LAYER MIRROR (MLM) 160 m lever arm MLM ID16A Mono Layer Mirror X-ray beam Page 23

24 ID16 MLM FIDUCIALISATION IN A CLEAN ROOM LABORATORY Page 24

25 ID16 MLM ALIGNMENT IN SITU Tie in the instrument (x,y,z) using the survey network Align the mirror support references to their nominal positions Page 25

26 ID16 NANO IMAGING BEAMLINE OPTICAL LAYOUT Source Point 0 m MLM 28.3 m 16 mrad Horizontal and vertical KB Focusing mirrors m e- beam X-rays are reflected and focused with mirrors at glancing angles less than 0.5 degrees 9 mrad. Sample 185 m 20 to 30 nm beam size Page 26

27 ID16 NANOIMAGING BEAMLINE MONO LAYER MIRROR (MLM) ALIGNMENT X-ray beam diameter ~1mm 8 mrad 1.6 mm This is the mirror surface seen by the beam when it is parallel to the beam This is the mirror surface seen by the beam when it is tilted 8 mrad to the beam Page 27

28 ID16 NANO IMAGING EXPERIMENTAL STATION Page 28

29 ANGLE AND DISTANCE MEASUREMENT Determining an angle with distances is inherently less precise than auto-collimation L= 0.2 m U(D) = 10 µm U(D) = 10 µm U(α) = 0.5 to 1 arc second (2.5 to 5 µrad) Page 29

30 PHASE II - EBS The ESRF Phase II EBS presents many significant alignment challenges We will discuss some challenges related to the beamlines Page 30

31 EBS AND THE BEAMLINES THE PROBLEM The new machine has a nominal design position. But the existing machine is not in its nominal position Vertical +0.8 mm Nominal Position Horizontal +1.1 mm Nominal Position Cell1-1.2 mm Cell32-2.1mm The simplest option is to align the machine in the position of the old machine 31

32 EBS AND THE BEAMLINES THE PROBLEM The main problem is that there is uncertainty as to where the actual beamline axes are with respect to their expected positions? Nominal beamline axis Machine and alignment errors Long term movements 32

33 EBS AND THE BEAMLINES THE PROBLEM Measurements were made on selected frontend and beamline primary slits to determine the difference between actual and expected positions The nominal beamline axis is determined by the magnet positions ID ID16 Straight Source Point Frontend Slit The measured beamline axis is determined by the slit positions Port End Primary Slit Page 33

34 EBS AND THE BEAMLINES THE PROBLEM The standard deviation in the difference between the measured and expected primary slit positions was 0.63 mm. This corresponds to a beamline angle uncertainty of 27 µrad at 1σ and implies alignment uncertainty of: ±3.2 mm at 2σ at 60 m in the EXPH, ±6.4 mm at 2σ at 120 m in the EX2, and ±9.7 mm at 2σ at 180 m on ID16. This means even if we align the new machine where the existing machine is, the photon beam will not necessarily be where it is today. Page 34

35 EBS AND THE BEAMLINES MEASURES We have decided the best way forward will be to Ensure all FE slits are remote servo-controlled. Measure the all of the beamline FE and primary slits to calibrate the beam trajectory. Install a beam viewer on every beamline. The beam viewers will be fiducialised and in principle the position of the beam can be measured. It is planned to be able to steer the beam onto the beam viewer with a precision better that 1 mm. Page 35

36 Thank you for your attention Page 36