Technical Specifications EuXFEL_FPC_HDC_stamped.pdf

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TECHNICAL SPECIFICATIONS

Updated September 2026 6202.90.42 :.taD

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Procurement of power couplers for the European XFEL accelerator complex Technical specifications

Table of contents

1- Introduction

2- Purpose of the present contract

3- Deliverables and supply parts

4- General description of the couplers

5- Performance specifications of the couplers

6- Definition of interfaces

7- Technical particular specifications

8- Drawings

9- Applicable technical documents

10- Contract follow up and milestones plan

11- Documentation requested

12- Protection of environment and of people

Annex:

1. Parts list

2. Drawings file

3. Cleaning and assembly procedure

4. DESY vacuum and material specifications

5. Factory acceptance tests records templates

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Procurement of power couplers for the European XFEL accelerator complex Technical specifications

1- INTRODUCTION

European XFEL Facility is a high energy X-ray generator based on a free electron laser, which is installed in Hamburg and is operational since 2017. This machine, based on the design of a linear super-conducting accelerator, providing an electron beam of energy from 10 to 17.5 GeV which, by the SASE principle («Self- Amplified Spontaneous Emission »), generate X-ray bursts of duration shorter than 100 femtoseconds. Total length of the plant is 3.3 km, composed of a 2 km long tunnel running between 10 and 15m underground, 5 X-ray beams and experimental stations dedicated to research in biology, in chemistry and on special materials. A High-Duty-Cycle (HDC) upgrade for the European XFEL LINAC is currently under study. A test accelerating module for HDC operation is planned.

Power couplers are some of the main elements of the super-conducting accelerator. They transmit the RF power from the electromagnetic power sources (Klystrons) to the superconducting cavities which accelerate the electron beams to about 23.6 MV/m at nominal power. Besides, couplers are the mechanical transition between the wave guides, the cryostat modules and the cavities, and have to preserve cleanliness and high vacuum of the cavities, an essential criterion for the good performance of the accelerator complex.

The super-conducting accelerator cryomodule is 12 m long and consists of a cryostat containing 8 cavities and 8 power couplers. These couplers go through the cryostat wall, and must consequently minimize thermal losses between the outside ambient and the cavity cooled by liquid Helium at 2 K. Between the extreme points, thermal screens at 70 K and 5 K are connected to the coupler’s body. Moreover, the cold end of the coupler must be able to move along the beam axis by about 2 mm during cool down.

Finally, the coupler must be leak proof between external atmospheric pressure and 3 different vacuum zones: cavity vacuum in the cold part, coupler vacuum in the “warm” part, and cryostat vacuum.

In addition to the HDC upgrade activities, a modification of the injector section is also planned. For this purpose, a dedicated set of modified power couplers is required for the injector cavities.

These Injector couplers are largely based on the HDC coupler design and differ only in the antenna length and in the geometry of the antenna tip (see drawings 172-CP-007, 172-CP-008). Apart from these modifications, all other functional, mechanical, vacuum, thermal, and RF requirements remain identical to those of the HDC couplers.

2- PURPOSE OF THE PRESENT CONTRACT

The purpose of this contract is the procurement of power couplers: • 10 HDC power couplers, based on European XFEL production experience • Only cold and warm parts are to be manufactured and delivered

Presentation of context:

On the technical hand, the experience gained by DESY in the previous manufacturing of 800 EuXFEL couplers allows to understand better the difficulties of manufacturing this product and to list its critical points:

• Stainless steel grade 316LN • Quality of brazing of stainless-steel parts • Ceramic to copper brazing • Stainless steel to copper brazing • Plating with ultra-pure copper • TiN thin film coating on ceramic windows • Final joining by Electron-Beam welding • Particle-free cleaning and baking processes • Tooling and fixtures necessary for assembly and control • Precautions for handling, storage, shipping • RF conditioning (controlled desorption of surfaces by functional RF power-up of the coupler in progressive steps) through its past experience, DESY has acquired a great expertise on these subjects, so that DESY is able to judge with a critical eye the different manufacturing processes.

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3- DELIVERABLES AND SUPPLY PARTS

Deliverables:

• Demonstration models: copper plating samples; • Plan of manufacturing processes; • 10 HDC power couplers (cold and warm parts only) and related documentation: dimension inspection and baking cycle sheets; • 10 HDC power coupler cleaned and assembled on the test stands.

Supply parts:

• 5 support frames, 30 e- probes electrical feedthroughs, tooling and fixtures including full metal angle valves, covers, flanges and test wave guides necessary for shipment of a batch of 10 couplers will be supplied by DESY.

Requested deliverables and supply parts are detailed in the parts list given in Annex 1.

Hand over conditions and date of supply of the test stand parts will be mutually agreed after the order is placed.

3.1 Qualification models:

Before the start of manufacturing, the contractor shall deliver two models intended to validate the manufacturing processes. These models shall be delivered to DESY for the investigation and will cover in particular the following subjects:

The contractor shall deliver:

• one sample consisting of two stainless steel tubes L = 100 mm connected by brazing with a bellow with int = 40 mm copper plated inside according to specification for cold part outer conductor;

• one sample consisting of two stainless steel tubes L = 100 mm connected by brazing with a bellow with out = 27 mm copper plated outside according to specification for warm part inner conductor;

These elements shall include the cylindrical tubes and bellows foreseen in the design, assembled with the foreseen brazing process.

3.2 10 HDC power couplers

As soon as possible but not later than twelve months after contract award, the contractor shall deliver the 10 power couplers, cold and warm parts, including all elements according to the part list (Appendix 1). These 10 power couplers shall be delivered completely assembled (warm parts filled with dry Nitrogen and cold parts under vacuum) each pair on a support frame. The 5 test wave guides and 30 e- probes electrical feedthroughs will be provided by DESY. Prior to this, the couplers should have followed the preparation process (phases of particle-free cleaning, assembly in clean room, vacuum pumping and leak test) as explained in details in article 7.17.

These 10 HDC couplers will be conditioned by DESY, Hamburg.

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4- GENERAL DESCRIPTION OF THE COUPLERS

A power coupler consists of the following main elements:

• a « warm » part composed of an external guide, an internal coaxial guide and bellows, with the RF metallic surfaces being Cu plated, a pumping port, two e- pick-ups ports, and a ceramic window
• a « cold » part composed of an external guide and bellows Cu plated on the RF side, one e- pick-up port, a ceramic window, and an antenna of high purity copper
• an interface assembly in replacement to the “capacitor”
• a transition box between the rectangular wave guide and the coaxial coupler
• a tuning mechanism for moving axially the antenna and a motorized transmission
• mounting parts and screws

The XFEL coupler’s design is shown on the following picture:

Wave guide to coax transition box Supports fixed on cryostat Connection to 70 K braids

Connection to 4 K braids

Qext tuning actuator Flange to cryostat Antenna Vacuum pumping port 1.8 K Flange to cavity

5- PERFORMANCE SPECIFICATIONS OF THE XFEL COUPLERS (for information only)

1. Frequency 1.3 GHz
2. Pulsed mode: rise time: 500 μs, flat top with beam: 800 μs Repetition rate 10 Hz Peak power 150 kW Average power 1.9 kW
3. CW mode: Average power 1.9 kW (nominal)
4. Thermal losses: at 2K flange: 0.06 W maximum at 4K flange: 0.5 W maximum at 70K flange: 6 W maximum
5. Tuning Q = 5x106 – 5x107, this requires an axial movement of the antenna of range ext

• 10mm, -10mm with 0.1mm repeatability

6. Maximum lateral displacement of cold flange:  5mm
7. Conditioning at room temperature: repetition rate 2 Hz, successive pulse widtht: 20 μs, 50, 100, 200, 400 μs with power up to Pmax = 1 MW, then 800 μs, 1300 μs with power up to Pmax = 500 kW

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6- DEFINITION OF INTERFACES

1. Interface with cavity: the coupler’s cold flange connects to the cavity flange with an aluminium gasket (also mounted on the test wave guide)
2. Interface with cryostat module: the warm part connects to the cryostat by the big flange
3. Interface to 4K shield: fixation to the copper ring for 4K interface
4. Interface to 70K shield: 8 M6 holes for fixation of 70K shield
5. Interface with vacuum pumping: CF40 flange on warm part
6. Interface with e- pick-ups: 3 CF16 flanges (2 on warm part, 1 on cold part)
7. Interface with wave guide: rectangular flange
8. Interface with arc detector: threaded hole 1/4"–36 UNS-2B
9. Interface with PT100 sensors: 3 holes Ø3 x 13 mm
10. Interface with pneumatics: 2 threaded holes G1/8" for connectors
11. Interface of coupler supports: fixations of 2 support frames on cryostat module
12. Interface with electronics control: the motor (stepping motor type) is part of the deliverables. The control electronics is not part of the deliverables. The interface is at the connector

7- TECHNICAL PARTICULAR SPECIFICATIONS

7.1 Requested architecture

Dimensions of surfaces exposed to RF currents, written in the set of drawings, are compulsory. In case areas of parts which are not exposed to RF are to be changed this is to be agreed with DESY.

7.2 Materials

The contractor shall provide inspection certificates type 3.1 according to EN 10204 for all used material. He shall respect in general the DESY material specifications given in Annex 4.

7.2.1 Basic recommended materials:

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7.2.2 Stainless steel: Stainless steels shall be of austenitic type with high content ratio of Cr, Mo, Ni. Inclusion property measured according to ASTM E45-97e1 shall be < 1,5ppm. Moreover, the stainless steel used in particular for CF flanges shall be made of alloy enriched with nitrogen to provide a high hardness (160 to 180 Brinell) for the knife edge which tightens the metallic gasket, even after heat treatment at 950°C. Stainless steel used in particular for the cold part shall have a relative magnetic permeability value  < 1,010. r

7.2.3 Copper: Grain size of raw material shall be evaluated according to EN ISO 2624 or ASTM E112-96 and shall be ≤ 150 m. Contractors shall provide a micrographic certificate with granulometry values.

7.2.4 Other metals: Use of other metals may be considered at the condition to demonstrate that they are well adapted to the expected functions: mechanical, electrical and thermal. Compatibility to electrical and thermal conductivities should be verified.

7.2.5 Screws: Screws are in general made of stainless-steel grade 304L (or grade A4 or class 8-8). To avoid possible seizing of fixation elements after cleaning in an ultrasonic bath, it is recommended to choose different materials for screw and nut. For instance, some nuts and screws are specified in CuNiSi alloy, which shows good mechanical properties and is non-magnetic.

7.3 Particular functionalities

Some particular issues, essential to the correct functioning of the power couplers in operation, are detailed below.

Ceramic windows geometry:

It is compulsory to use the exact dimensions of the ceramic windows to obtain the required RF performance of the coupler, in particular the geometry of the end grooves, including the brazing groove itself and a break in the slope which results in a decrease of the local electric field concentration. The metallization layer (of type 20 to 30μm of Mo-Mn and 3 to 5μm of Ni) must stop precisely at the edge of the slope break.

TiN layer on ceramic windows:

The design experience in RF power systems has shown the advantage of a thin layer of TiN deposited on ceramic windows in order to decrease the secondary electron emission coefficient (to avoid the risk of « multipacting ») and to get rid of the surface electrical charges (to avoid breakdowns). For this reason, both ceramic windows of the XFEL coupler shall be coated with a TiN layer of 10 nm nominal thickness (minimum tolerance 5 nm, maximum 30 nm): on all surfaces for the cold window, only on the vacuum side for the warm window. The contractor shall propose a process for this deposition and a procedure to check the film thickness obtained (for instance with a quartz scale).

A good electrical RF contact is also required in the connection between cold and warm parts. For the outer conductor, this is made by the copper seal clamped between the 2 CF100 flanges. For the inner conductor, this is made by the flat contact of the right tip (drawing I72-WP-002) to the Cu antenna.

Thermal power transfer:

To withdraw the thermal power dissipated in the coupler two elements, coupler 4K and 70K shields, are used (see interface definition in paragraph 6):

• For the large cold flange: a maximum power of 6 W is conducted to the 70 K shield
• For the copper half-rings brazed on the cold part between bellows and cavity flange: a maximum power of 0.5 W is conducted to the 4 K shield

Connection between warm and cold parts:

Warm and cold outer conductors are connected by the CF100 flanges which are supported by a sliding support fixed on the warm part.

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7.4 Copper plating

The objective of the Cu plating of the stainless-steel surfaces is to transmit the RF power with a high conductivity, but also to limit the power dissipated by resistive losses resulting from the surface currents and consequently the heating of the coupler in operation. However, the plating may not exceed a certain thickness in order to avoid a direct thermal bridge from ambient temperature to the connections at 70 K, 4 K and 2 K and thereby generate unacceptable high static thermal losses. The contractor shall indicate the copper plating process chosen and will define the ways and equipment for thickness control.

The contractor shall provide the control reports concerning the specifications listed below, necessary to validate the copper plating process.

Thickness of the Cu plating:

Layer of nickel or gold: ≤ 2 μm Thickness of the inner copper layer (inner surface of outer conductor): 10 μm  5 μm Thickness of the outer copper layer (outer surface of warm inner conductor): 150 μm  30 μm

Quality of the Cu plating:

The deposited copper shall have low hydrogen content. The baths may contain organic brightener agents at the condition that they do not reduce the RRR.

Adhesion of the Cu plating:

A perfect adhesion of the copper plating must be obtained, on the bellows as well as the other tubular parts. The adhesion shall be demonstrated on samples by the contractor, the test consisting in a thermal shock in a bath of liquid N followed by an ultrasonic bath (nominal power 10 W/liter) in pure water at 2 100°C for 10 minutes and check of possible loose particles.

Electrical conductivity:

The contractor shall provide Cu-plated validation samples (see 3.1) in order to measure the electrical conductivity of the plating (σ > 4.109 Ω-1m-1) and the RRR (« Residual Resistivity Ratio ») which has to be between 10 and 60 after the final baking of the finished coupler.

Surface roughness:

The surfaces exposed to the RF power shall in general have a roughness Ra < 1.6 μm, except for the sealing surface of the flanges having a Ra < 0.8 μm, also after copper plating.

7.5 Welding specifications

All electron beam welds are at full penetration 100%.

• the contractor shall take into account in the preparation of parts the shrinkage due to welds in order to obtain the desired final dimension. Tests shall be made to evaluate this shrinkage.
• to protect internal surfaces by zirconium, tantalum, or other material screens against metal vapour and against spattering of Cu particles on RF surfaces (especially the ceramic surfaces), the screens have to be dismounted after welding.
• to ensure full penetration and exhibit the smallest possible bulge inside on the HF surface.

Concerning the final roughness, it is essential to eliminate peaks, sharp edges or small spherical features resulting from welds on surfaces exposed to RF, taking care not to leave any residues harmful to ultra- vacuum. This can be easily controlled by passing a finger with a cotton glove over the weld seam. Weld seams may be brushed (only if necessary), with brushes of the same material as the brushed material or Molybdenum wool. Scratches (before Cu plating) deeper than 30 μm should be avoided on RF surfaces of the internal conductor, and 20 μm for the ones of the external conductor. Brushed samples shall be provided for analysis and validation of the brushing process. Grinding is forbidden, but milling may be done carefully. Ceramic windows have to be protected against copper vapor during welding process.

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7.6 Brazing specifications

The contractor shall perform preliminary validation tests (see 3.1) for brazing used for the manufacturing of the couplers. The strong brazing shall be made in a clean vacuum oven, brazing under H atmosphere 2 is not desired, brazing under partial pressure of N is allowed. 2

Three types of brazing can be identified in the manufacturing process of the coupler:

i. Brazes between copper parts and stainless-steel parts (example of a possible process: contributing alloy CuSn, brazing in vacuum at a temperature of 1020 °C).

ii. Brazes between ceramic windows and copper rings (examples of possible processes: contributing alloy CuAg with brazing in vacuum at temperature of 780 °C, or contributing alloy CuAu with brazing in vacuum at temperature of 1040 °C). Ensure protection if the inner and outer surfaces of the window during brazing to avoid any contamination by braze vapours: a solution is to protect the window by two other concentric ceramics which will be removed after brazing.

iii. Brazes between stainless steel parts.

It is essential that the presence of silver, as well as silver alloy, should be avoided on RF surfaces. Before first use and regularly, the brazing oven shall be entirely cleaned. Before each use, dust shall be blown away from the brazing equipment with dry nitrogen.

Concerning final roughness, it is essential to eliminate peaks or sharp edges resulting from brazes on surfaces exposed to RF, taking care not to leave any residues harmful to ultra-vacuum. Brazes may be brushed only, if necessary, with brushes of the same material as the brushed material or Molybdenum wool. Scratches (before Cu plating) deeper than 30 μm should be avoided on RF surfaces of the internal conductor, and 20 μm for the ones of the external conductor. Brushed samples shall be provided for analysis and validation of the brushing process. Grinding is forbidden, but milling may be done carefully.

7.7 Assembly sequence

The recommended assembly sequence of power coupler is the following:

• Brazing of stainless-steel parts
• Oven firing of stainless-steel parts in vacuum at 950°C during 2 hours to eliminate hydrogen (could be part of the brazing process)
• Brazing of Cu collars to stainless steel parts
• Cu plating of stainless-steel surfaces on RF side
• Oven firing in vacuum of copper/steel assemblies at 400°C during 2 hours followed by an US bath
• Brazing of Cu collars to ceramic windows
• TiN coating of windows assemblies
• Final assembly by 2 electron-beam welds at the copper collars

Other types of assembly and processes may be considered for cost and time reasons. Those should be analysed and justified by the contractor and agreed by DESY.

7.8 Specifications for leak tightness

In general, coupler parts should follow the DESY guidelines for UHV components (version 1.6 dated 22.09.2010 and given in Annex 4).

Brazing and welding joints should be leak tested during the validation phase of the processes and during the manufacturing of the couplers as well. The contractor shall use a helium leak detector having sensitivity better than 10-11 Pa.m3/s and calibrated daily using a reference leak of 10-10 Pa.m3/s.

Concerning the methods of leak tests, one will refer to the EN 1779 standard.

For the leak tests of the parts (intermediate tests or final tests), only use oil-free dry vacuum pumping systems to avoid any contamination of internal surfaces by hydrocarbons (these cannot be totally eliminated by a final cleaning).

Flange sealing will be done by copper seals of OFS quality (OFHC copper with addition of Ag).

Other solutions may be considered after approval.

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7.9 Specifications for cleaning

Several cleaning processes may be used according to the in-house standards and to the local regulations. A typical procedure is as follow:

i. detergent cleaning in ultrasonic bath at 60°C ii. ultra-pure de-ionized water rinsing in ultrasonic bath at 80°C iii. ethylic alcohol rinsing iv. drying with dry warm nitrogen

Parts made of stainless steel may have an intermediate etching in a bath with nitric and fluorhydric acids. Parts made of copper may have an intermediate etching in a bath with sulfamic or sulfochromic acid.

7.10 Specifications for handling

Handling of the parts and sub-assemblies shall be done with non-fluffy white gloves made either in batiste, non-powdered latex or non-powdered nitrile. Absolutely avoid all traces of fingers or greasy spots.

Handling environment should be clean, free of hydrocarbons vapours.

7.11 Recommendations for dimensional control

The contractor shall provide a control plan for the manufacturing in production for approval. A full 100% control shall be done on the 1st unit and by sampling during the production process, other units may be partially controlled. A dummy assembly will be part of the control plan.

The roughness of the surfaces exposed to the RF power shall in general have Ra < 1.6 μm, except for the sealing surface of the flanges having Ra < 0.8 μm.

Acceptable scratches height on RF surfaces before Cu plating: Rmax(int) < 30 μm for the internal conductor, Rmax(ext) < 20 μm for the external conductor. Acceptable scratches depth after Cu plating: Rmax(int) < 20 μm, Rmax(ext) < 10 μm.

Visual inspections will be part of the control plan to check the absence of sharp edges, peaks, holes and scratches on surfaces exposed to RF power, before and after copper plating. The cotton glove test shall be part of the control procedure. Depth of scratches shall be measured with a device of type profilometer or perthometer on samples representative of the series.

7.12 Specification for thermal baking of stainless steel

See DESY material specifications. To obtain after final assembly a low desorption rate, stainless steel parts must be fired in a vacuum oven (P< 10-5 hPa) during 2 hours ( 0.1h) at 950°C ( 25°C). This firing may be part of the brazing process. For bellows in particular, the firing (if possible) must be made before hydroforming the metal and no firing after (experience showed that bellows fired after forming undergo a structural change which decreases greatly their elastic limit).

7.13 Specification for thermal baking of metallic sub-assemblies

After the copper collars have been brazed to the stainless-steel parts, surfaces exposed to RF receive copper plating as specified in paragraph 7.4. To ensure low desorption rate at the end, a thermal baking of these sub-assemblies must be performed in a vacuum oven (P< 10-5 hPa) during 2 hours ( 0.1h) at 400°C ( 20°C). This baking is also a test for the copper plating: copper particles might get loose in case of a bad adhesion.

7.14 Surfaces under vacuum

Cleanliness of surfaces under vacuum with respect to desorption shall be verified by mass spectrum analysis. See DESY vacuum specifications in Annex 4.

7.15 Specifications for storage and packing

Manufactured parts should be stored, before and after assembly, in cabinets filled with dry nitrogen.

Packing for possible intermediate transport:

• sub-assemblies shall be transported in stainless steel containers (containers must be pumped out and filled with dry nitrogen, then sealed)
• other vacuum parts without container: packed first in non-fluffy paper then in a sealed bag

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Bags made of polymer plastic should be avoided (these generate molecules of hydrocarbons which pollute the RF surfaces) and aluminium foil (generating metallic particles).

7.16 Identification marking

The main components of the coupler (cold part, warm part, wave guide interface box) shall be identified by individual marking of a serial number. This number should be readable by the eye or in the form of a bar code, either engraved on the element either on a sticker firmly attached. This marking shall:

• be visible easily
• use characters of regular height
• be readable easily
• be indelible and withstand baking
• represent a reference for tracing the manufacturing and control history

The marking convention for HDC couplers is MMM-PP-HDC-XXX, where:

• MMM is the contractor’s acronym
• PP is the part’s name
• XXX is the serial number starting with 001.

7.17 Couplers cleaning and assembly

Couplers cleaning and assembly is explained in details in Annex 3, the main phases are the following:

• reception of main parts in their individual container filled with N2 and inventory of other parts
• cleaning of all parts with ultra-pure water in ultrasonic bath in clean room ISO 14644 class 6
• drying under laminar flow in ISO class 4 clean room
• assembly of 2 cold parts on test wave guide in ISO class 4 clean room
• assembly of warm parts on the cold parts and accessories, mounting on the test structure (two couplers on each one) in clean room ISO class 6
• bring the test structure outside the clean room, install vacuum connections under laminar flow
• vacuum pumping cold and warm parts, leak tests

7.18 Delivery of couplers

The couplers shall be transported and delivered to DESY after manufacturing in the following way:

• packing and transport of couplers in pairs mounted on a support frame
• the 2 cold parts and the 2 warm parts assembled on the test wave guide and remaining filled with dry nitrogen filtered to ASTM 10, in order to avoid any contamination by disconnecting the cold parts (opening the cold parts or the cavity would automatically induce contamination of the internal surfaces)
• the other parts packed in non-fluffy material, free of polymers

After delivery at DESY these couplers will be baked at 130°C, RF-conditioned and then assembled on cryomodules.

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7.19 Couplers conditioning at room temperature (for information only)

Conditioning consists of controlling the gas desorption by the impact of electrons on the RF surfaces. This is a critical and long operation, but a compromise must be found between conditioning speed and sparking risk.

For information, the main sequences are the following:

• mounting the wave-guide interface box
• mounting the copper gasket (previously a capacitor)
• mounting the tuning mechanism
• adjustment of frequency tuning by use of a 1.3 GHz RF generator
• switching on ion pumps until vacuum reaches 10-9 hPa
• assembly on the RF test station, connection of wave-guides and diagnostics
• RF conditioning by steps of increasing power at increasing pulse widths: ▪ successively 20, 50, 100, 200, 400μs from 0 to 1 MW, repetition rate 2 Hz ▪ then 800, 1300μs from 0 to 500 kW ▪ at 1300μs sweeping from 0 to 500 kW 3 times
• filling with dry nitrogen of purity 99.999% filtered to ASTM 10 (and using a stainless steel tubing), closing valves on test cavity and couplers, disconnecting
• storage in dust free cabinets

8- DRAWINGS

A file of drawings is included in Annex 2. Geometrical tolerances shown in the drawings are the result of RF simulations and are compulsory for the XFEL power couplers.

9- APPLICABLES TECHNICAL DOCUMENTS

The contractual technical base of the contract is defined by the following documents listed in decreasing hierarchical order:

1. Technical specifications
2. Drawings
3. DESY specifications for material and vacuum
4. European standards or equivalent DIN or ISO standards
5. ISO 9001:2000 standards for quality assurance

In case of conflict between two of these documents, the highest one in hierarchy shall be applied.

10- CONTRACT FOLLOW-UP AND MILESTONES PLAN

Communications with DESY / European XFEL Company

As soon as the contract is signed, both, the contractor and DESY shall name a person in charge of project management who will be the main contact point.

Required milestones:

Exact dates shall be proposed by the contractor as soon as possible.

1. Production start-up meeting (remote meeting is possible);

2. Copper plating samples (see 3.1) delivery;

3. DESY copper plating investigation and delivery of the report;

4. Review and approval of vendor manufacturing drawings by DESY;

5. Start of production;

6. Inspection and acceptance by DESY of all brazed stainless-steel parts;

7. Copper plating;

8. Inspection and acceptance by DESY of all copper plated parts;

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9. Inspection and acceptance by DESY of all ceramic windows after TiN coating;

10. Final electron beam welding of parts;

11. Final inspection and acceptance by DESY before assembly on the test stand;

12. Delivery to DESY.

11- DOCUMENTATION

Documentation is part of the required deliverables. The language to be used in all documents is English. The requirements are detailed below. The delivered documentation will include all documents created by the contractor in the course of the execution of this contract: − Time schedule − Documents for contract management and supervision: a. Project management structure at the contractor b. Quality Plan c. Change management and documentation − Documents issued during production: a. ‘as built’ drawings b. material certificates c. records of specific and critical processes d. certificates of conformity e. Quality control records according to QP − Documentation with delivery of power couplers to DESY a. Parts list and identification b. Factory acceptance tests records, see Annex 5.

12- PROTECTION OF ENVIRONMENT AND OF PEOPLE

The contractor commits himself to take the necessary measures in order:

• to avoid dumping of products which may be toxic or poisonous or harmful to the environment, by respecting the rules in effect on the sites of production for this contract,
• to ensure the protection of individuals engaged in the course of this contract

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