sp39100065-1_1micron_KB_ESD_summary_112608.pdf

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ENGINEERING

SPECIFICATION

DOCUMENT (ESD)

Doc. No.

LUSI SUB-SYSTEM

CXI

Engineering Specifications Summary for the CXI 1 micron KB

System

Prepared by:

Sébastien Boutet Signature Date CXI Instrument Scientist

Reviewed by:

Paul Montanez Signature Date CXI Lead Engineer

Reviewed by:

Signature Date

Approved:

Darren Marsh Signature Date Quality Assurance Manager

Approved:

Tom Fornek Signature Date LUSI Project Manager

Revision Date Description of Changes Approved

L C L S U L T R A F A S T S C I E N C E I N S T R U M E N T S

ESD CXI 1 micron KB System

Table of Contents

1. Overview

2. Scope

3. Applicable Documents, Specifications and Codes

3.1. SLAC Specifications

3.2. Other Specifications

4. General Requirements

4.1. Location

4.2. Environment

4.3. Lifetime

5. Summary of the Specifications

5.1. Mirror Substrates

5.1.1. Substrate Specifications

5.1.2. Other Requirements

5.2. Mirror Mechanics

5.2.1. Mirror Support System

5.2.2. Other Specifications

5.2.3. Vacuum Enclosure

5.2.3.1. Vacuum Ports

5.2.4. Support Stand

1. Overview The Coherent X-ray Imaging (CXI) instrument to be built at the Linac Coherent Light Source (LCLS) by the LCLS Ultrafast Science Instruments (LUSI) project on the SLAC National Accelerator Laboratory site requires a mirror system to produce a 1x1 micron2 FWHM focal spot at the sample. The mirror system shall be made of 2 mirrors each with an elliptical figure and arranged in a Kirkpatrick-Baez (KB) configuration rotated by 45 degrees. The system is known as the CXI 1 Micron KB System or KB1.

The LCLS will produce a laser-like beam of X-rays in the 800 to 8300 eV range for the fundamental energy. Also, the 3rd harmonic will be present at up to 25 keV. The CXI instrument will use the hard X-ray branch which uses 2 offset mirrors that reflect energies between 2 keV and 25 keV. The KB mirrors will be located 420 m away from the source, which ranges in size from 60 µm to 78 µm FWHM, depending on the energy. The X-ray beam at the mirror location will range from 500 µm to 1500 µm depending on the energy.

The KB mirror combination shall reflect more than 75% of the X-rays over the 2-18 keV range. This will be achieved by coating the mirrors with two strips. The first strip will be a Silicon Carbide (SiC) monolayer and the second strip will be a bilayer consisting of a heavy material (either Rhodium (Rh) or Ruthenium (Ru)) deposited underneath a thin layer of Silicon Carbide (SiC).

These mirrors will be located in an Ultra-High Vacuum (UHV) environment (10-9 Torr).

They require a very precise positioning system with the mirrors located inside a vacuum enclosure which will be mounted on a stable stand.

2. Scope This document contains the specifications for the fabrication and delivery of a KB mirror system capable of producing a focal spot of roughly 1 µm x 1 µm (FWHM) for the CXI instrument built by LUSI at LCLS. Here, we say roughly 1 µm x 1 µm (FWHM) because the source size and location varies with the photon energy and therefore the focal spot will vary with energy and it will not be possible to obtain a 1 micron focus at all energies. The focus shall also not be smaller than 1 µm x 1 µm (FWHM) at any energy within the range of interest but may be larger than 1 µm x 1 µm (FWHM) at the lower energies. The specifications described in this document were chosen to satisfy this requirement. Multiple activities and components are required to build the complete mirror system. They are as followed.

Mirror Substrates

Mirror Coating

Mirror Metrology

Mirror Mechanical Support System

Vacuum Enclosure

Support Stand

All the requirements are summarized in Section 5 at the end of this document.

3. Applicable Documents, Specifications and Codes

3.1. SLAC Specifications

• SLAC document No. SP-391-000-25, “Physics Requirements for the CXI 1 micron

KB System”

• SLAC document No. SP-391-000-19, “Physics Requirements the CXI Instrument”

• SLAC document No. SP-391-001-41, “Physics Requirements the CXI 1 micron Sample Chamber”

• SLAC document No. SP-391-001-42, “Physics Requirements the CXI 1 micron Precision Instrument Stand”

• SLAC drawing No. DS-391-000-36, “Mechanical Design Standards Supplement”

• SLAC drawing No. SC-700-866-47, “Specification Kly & Vac Machining Fluids”

• Fed-STD-595B, “Colors Used in Government Procurement”

3.2. Other Specifications

• MIL-PRF-13830B: “Optical Components for Fire Control Instruments; General

Specification Governing the Manufacture, Assembly, and Inspection of.”

4. General Requirements

4.1. Location

The vacuum enclosure of the KB mirror system will be located in experimental hutch 5 in the Far Experimental Hall of LCLS, known as FEH Hutch 5.

The midpoint between the 2 mirrors along the x-ray beam shall be located 384 m downstream of the exit of the LCLS undulator, which produces the X-ray beam. This same midpoint shall be located 8 m upstream of the focal point. The spacing between the 2 mirrors shall be kept to a minimum to minimize the overall length of the system.

4.2. Environment

The temperature and relative humidity in the FEH Hutch 5 will be maintained at (22.2°C +/-0.3°C), and 45% +/-10%, respectively.

The LUSI project will provide a temperature-controlled enclosure to encase the KB mirror system. This enclosure shall have a thermal stability of ±0.01 degree Celcius. The mirror system shall be designed to meet the thermal stability requirements listed in this document when enclosed in this environment with temperature controlled to ±0.01 degree Celcius.

4.3. Lifetime

The expected service life of the device is 10 years.

5. Summary of the Specifications

5.1. Mirror Substrates

The mirror substrate vendor shall provide 2 mirrors, 5 test coupons and 1 blank substrate meeting the requirements summarized below.

5.1.1. Substrate Specifications

Parameter Value Value Units Comment Mirror 1 Mirror 2 1 Mirror Shape Tangential ellipse 2 Clear aperture length 350 mm 3 Clear aperture width 30 ≥ width ≥ 12 mm 4 Mirror Length 375 ≥ length ≥ 360 mm 5 Mirror Width 60 ≥ width ≥ 45 mm 6 Mirror Thickness >50 mm 7 Substrate material Si <100> 8 Figure height error <1.00 nm rms Over dimensions from 1mm to the clear aperture size from best-fit ellipse

9 Mid-spatial roughness <0.25 nm rms Over the 10-3 to 0.5 µm-1 frequency range

10 High-spatial roughness <0.25 nm rms Over the 0.5 to 50 µm-1 frequency range

11 Tangential Slope error <0.25 µrad rms

Over dimensions from 1mm to the clear aperture size from best-fit ellipse

12 Sagittal Slope error <2 µrad rms

Over dimensions from 1mm to the clear aperture width from best-fit sagittal radius

13 Sagittal radius of curvature

>400 m

14 Focal length 8.2 7.8 m 15 Maximum incidence angle

3.4 mrad

16 Average incidence angle

3.364 3.363 mrad

17 Distance from source 420 m 18 Vacuum pressure <10-9 Torr

Table 1: Summary of the mirror substrate specifications

5.1.2. Other Requirements

Item Comments

Surface finish on non-optical surfaces

Ground and wet-chemical etched

Operating environment and service temperature range

Normal operation in ultrahigh vacuum (UHV) at ~20°C. UHV bake out at 125°C.

Mirror Coating Provided by Others Test Coupons Provide 5 test coupons polished the same way as the full mirrors Blank Si Substrate Provide a blank Si substrate with reduced figure and roughness requirements Inspection After initial shaping of the mirrors Metrology Provide metrology plan to SLAC. Perform metrology after final polishing is complete Handling and Cleaning Full, Ultrahigh Vacuum (UHV) practice required. Provide a summary of proposed handling and cleaning procedures in the "Handling and Process Plan".

Packaging and Shipping Vendor shall be responsible for design and fabrication of the mirror shipping container(s). Best protection against contamination and shock/vibration is essential. All-metal, dust-free interior-most enclosure desirable. Include a description of proposed packaging and shipping arrangements in the "Handling and Process Plan"

Documentation Include a description of proposed characterization metrology in the "Inspection Test Procedure".

Supply machine-readable raw data sets for all metrology performed of mutual agreement.

as part of the "Inspection Test Report".

Describe file format and supply necessary constants and parameters to permit independent data analysis of the raw data.

Quality Assurance Provide detailed project schedule Identify project manager as single point of contact Monthly teleconferences with SLAC

Table 2: Summary of all requirements to be satisfied by the mirror substrate vendor.

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5.2. Mirror Mechanics

A single vendor shall be responsible for all the mirror mechanical system specifications and requirements summarized below.

Three distinct components are identified

• The in-vacuum mirror support system (Mirror Support System)

• The Vacuum Enclosure in which the Mirror Support System is located

• The Support Stand on which the Vacuum Enclosure in mounted

All reporting, documentation and quality assurance requirements apply to each component.

5.2.1. Mirror Support System

Figure 1: Definition of the KB mirror system axes of rotation

Mirror Motion Nominal Position Range Resolution Repeatability Motorized Manually

Adjusted Vibrational

Stability Thermal Stability

1 x1 0 -7 mm < x < 7 mm 4 µm 4 µm Yes No 1 µm 10 µm

1 y1 0 -10 mm < y < 4 mm 4 µm 4 µm Yes No 0.1 µm 1 µm

1 z1 -8.2 m (from focus)

± 20 mm 8 µm 8 µm Yes No 1 µm 1 µm

1 Grazing angle (θ1) 3.364 mrad 2.5 mrad < θ < 3.5 mrad 0.5 µrad 0.5 µrad Yes No 0.01 µrad 0.1 µrad

1 In-plane rotation (ψ1) 0 -10 mrad < ψ < 10 mrad 1 mrad 1 mrad No Yes 0.1 mrad 0.1 mrad

1 Perpendicularity (φ1) 0 -100 µrad < φ < 100 µrad 5 µrad 5 µrad Yes No 1 µrad 1 µrad

2 x2 0 -7 mm < x < 7 mm 4 µm 4 µm Yes No 1 µm 10 µm

2 y2 0 -10 mm < y < 2 mm 4 µm 4 µm Yes No 0.1µm 1 µm

2 Grazing angle (θ2) 3.363 mrad 2.5 mrad < θ < 3.5 mrad 0.5 µrad 0.5 µrad Yes No 0.01 µrad 0.1 µrad

2 In-plane rotation (ψ2) 3.4 mrad -10 mrad < ψ < 10 mrad 1 mrad 1 mrad No No 0.1 mrad 0.1 mrad

2 Perpendicularity (φ2) 0 -100 µrad < φ < 100 µrad 5 µrad 5 µrad No No 1 µrad 1 µrad

2 z2 -7.8 m (from focus)

Fixed Fixed Fixed Fixed Fixed 1 µm 1 µm

Table 3: Summary of the mirror mechanical motion specifications

5.2.2. Other Specifications

45 degree geometry Provide an option for mounting the mirrors at 45 degrees from the standard KB configuration to deflect the beam in the horizontal direction only. SLAC will decide to exercise the option or not after the receipt of the proposal

Mirror mounting Preserve the figure of the mirrors without the specifications of the substrates Clear aperture of at least 2 mm x 12 mm

Motion limits Two sets of limit switches, for small and large motions Motions limits to be implemented for beam confinement by SLAC Hard stops for full range of motion

Expected lifetime of device

10 years

Dimensions inside vacuum

Length: < 0.8 m Width : < 350 mm from center in the –x direction No restriction in the +x direction Height: No restriction other than the beam height of 1.4 m and ceiling of 3 m

Vacuum Normal operation in ultrahigh vacuum (UHV) at ~20°C. UHV bake out at 125°C.

Thermal issues <34 mW of heat will be absorbed by the mirror substrates during operations. Vendor to perform analysis to demonstrate the performance of the system given this heat load Radiation protection The LCLS beam will damage most materials except for light materials. Only the optical surface shall be exposed to the beam.

Any other surface exposed to the beam shall be protected with a B4C shield B4C shield to protect the leading edge of the mirrors

Operating conditions SLAC to provide a thermal enclosure stable to within 0.01 degree Celcius Design and Analysis Vendor design to include :

Interface definition Component design Stress and thermal analysis Reliability analysis System performance analysis Verification and test plans Integration of the mirror substrates into the mechanical system

Materials Provide list of materials to be used Electrical Provide all vacuum feedthroughs and UHV connectors Controls and motors Use device with existing EPICS drivers to the extent possible Handling and Cleaning Full, Ultrahigh Vacuum (UHV) practice required. Provide a summary of proposed handling and cleaning procedures in the "Handling and Process Plan".

Packaging and Shipping Vendor shall be responsible for design and fabrication of the system shipping container(s). Best protection against contamination and shock/vibration is essential. All-metal, dust-free interior-most enclosure desirable. Include a description of proposed packaging and shipping arrangements in the "Handling and Process Plan"

Documentation Include a description of proposed characterization fabrication, assembly and inspection in the "Inspection Test Procedure".

Supply machine-readable raw data sets for all measurements performed of mutual agreement.as part of the "Inspection Test Report".

Describe file format and supply necessary constants and parameters to permit independent data analysis of the raw data.

Provide all as-built drawings to SLAC in PDF format and all 3D models in agreed upon formats Provide a qualification and verification matrix with pass/fail grades after final testing Report all non-conformance with the specifications to SLAC Part marking Vendor to inscribe all parts, assemblies and sub-assemblies with a unique serial number, whenever possible Quality Assurance Provide detailed project schedule Identify project manager as single point of contact Monthly teleconferences with SLAC Configuration control to be implemented by vendor with a formal change process to drawings Reviews Conceptual Design Review : 2 months after award Preliminary Design Review : 4 months after award Final Design Review: 10 months after award Manufacturung Readiness Review: Prior to start of fabrication Pre-Ship Review: Acceptance testing prior to shipping Installation at SLAC Vendor responsible for assembly and installation at SLAC

SLAC will provide all necessary assistance Table 4: Summary of all the mirror mechanical specifications and requirements

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5.2.3. Vacuum Enclosure

Vacuum Normal operation in ultrahigh vacuum (UHV) at ~20°C. UHV bake out at 125°C.

Dimensions 0.8 m < Length < 1.15 m Width : < 450 mm from center in the –x direction No restriction in the +x direction Height: No restriction other than the beam height of 1.4 m and ceiling of 3 m

Mounting Reproducible to within 0.1 mm Environment Vacuum enclosure to be located inside a thermal enclosure controlled to

0.01 degree Celcius Stability requirements to be met under these conditions

Fiducialization Provide external references outside the vacuum enclosure for surveying External references to be at known positions relative to the mirrors inside vacuum

Maintenance and Accessibility

Design to allow removal of the in-vacuum components without removing the vacuum chamber from the beamline Multiple access ports to be provided for small maintenances Removal top of the chamber with fixtures for lifting with a crane No trip hazards, pinch points, loose cables

Table 5: Summary of all specifications and requirements for the Vacuum Enclosure.

5.2.3.1. Vacuum Ports

Port type or use Orientation Location Purpose

1 Entrance Port (6” non-rotatable) Along the beam Upstream of chamber, centered on the beam Let the beam in

2 Exit Port (6” rotatable) Along the beam Dowstream of chamber, centered on the beam Let the beam out

3 Viewport (4.5”) Along ψ1 axis Midpoint along z of mirror

Future addition of interferometer

4 Viewport (4.5”) Along θ1 axis Midpoint along z of mirror

Future addition of interferometer

5 Viewport (4.5”) Along ψ2 axis Midpoint along z of mirror

Future addition of interferometer

6 Viewport (4.5”) Along θ2 axis Midpoint along z of mirror

Future addition of interferometer

7 Vacuum gauge (2.75”) Any Anywhere Measure the pressure

8 Vacuum gauge (2.75”) Any Anywhere Measure the pressure

9 Rough pumping (2.75”) Any Anywhere Pump down the enclosure from atmosphere 10 Ion Pump (6”) Any Bottom of enclosure Create Ultra-high vacuum

11 Feedthrough (6”) Any Near the back side of mirror

Connect cables for motorized motions

12 Feedthrough (6”) Any Near the back side of mirror

Connect cables for motorized motions

13 Miscellaneous (6”) Any Anywhere Future expansion

14 Miscellaneous (6”) Any Anywhere Future expansion

15 Miscellaneous (2.75”) Any Anywhere Future expansion

16 Miscellaneous (2.75”) Any Anywhere Future expansion

Table 6: List of required vacuum ports for the Vacuum Enclosure

5.2.4. Support Stand

Stability Shall meet the vibrational and thermal requirements of the mirror support system described above

Dimensions 0.8 m < Length < 1.15 m Width : < 450 mm from center in the –x direction No restriction in the +x direction Height: Must position the mirrors at a beam heigh of 1.4 m

Structural issues Design to be certified by the SLAC Earthquake Safety Committee is the total weight of the system exceeds 400 pounds Vendor to allow 6 weeks for SLAC approval

Design shall satisfy the 10CFR851 requirements for pressure vessels Positioning Allow the vacuum enclosure and mirror support system to be positioned over a ± 12.5 mm range for coarse positioning in case of beam drifts over long periods

Color Painted with red color matching the US Federal Standard FS11140 Table 7: Summary of all specifications and requirements for the Support Stand.