Attachment G - EIC-VSG-SPC-023 Tech Spec Rev 0 04-18-2024.pdf

Electron-Ion Collider, Brookhaven National Laboratory

Doc No. EIC-VSG-SPC-023 Author: Charles Hetzel Effective Date: April 18, 2024 Review Frequency: N/A

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

TECHNICAL SPECIFICATION

for the

Design and Fabrication of Components for use in the EIC Vacuum System

Quality Classification: A-3

Prepared By:

_________________________________ Date: __________________ Charles Hetzel, EIC Vacuum Group Leader

Reviewed By:

Dan Weiss, C-AD Vacuum Group Leader

Approved By:

Joseph Tuozzolo, Technical Division Group Leader

DocuSign Envelope ID: 462820BD-55F0-48B3-8422-01EE66644C2C

4/18/2024

4/25/2024

4/25/2024

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

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Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

REVISION HISTORY

Revision # Effective Date Summary of Change

00 4/18/2024 Initial Release

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

Table of Contents

1 SCOPE

1.1 Background

2 APPLICABLE DOCUMENTS

3 REQUIREMENTS

3.1 Technical/Performance Characteristics

3.2 Materials

3.2.1 UHV Compatible Materials

3.2.2 Incompatible Materials

3.3 Fabrication

3.3.1 Machining

3.3.2 Cleaning

3.3.3 Welding and Brazing

3.3.4 Assembly

3.4 Marking and Serialization

3.5 Packaging/Shipping

4 VERIFICATION

4.1 Dimensional Inspection

4.2 Leak Test

4.3 Bakeout

4.4 RGA Test

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

LIST OF ACRONYMS

AMU Atomic Mass Units ASME American Society of Mechanical Engineers ATP Acceptance Test Procedure BNL Brookhaven National Laboratory BSA Brookhaven Science Associates COTS Commercial Off-The-Shelf EBW Electron Beam Weld EIC Electron-Ion Collider ESR Electron Storage Ring ESH Environment, Safety and Health IP Sputtering Ion LBW Laser Beam Weld NEG Non-evaporable getter RGA Residual Gas Analyzer SEM Secondary Electron Multiplier SOW Statement of Work TIG Tungsten Inert Gas UHV Ultrahigh Vacuum VAR Vacuum Arc Remelt

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

Technical Specification for the Design and Fabrication of Components for use in the EIC Vacuum System

1 SCOPE

This specification, in conjunction with the associated Statement of Work (SOW), drawings, specification, and other applicable documents, provides the general requirements in the design, material selections, fabrication and workmanship, cleaning, assembly, inspection, quality assurance, and packaging of vacuum chambers, parts, and components ("Components," hereafter) to be used in the Electron-Ion Collider (EIC) Ultrahigh Vacuum (UHV) systems at Brookhaven National Laboratory (BNL) managed by Brookhaven Science Associates (BSA). It is the responsibility of the manufacturers ("Vendor" hereafter) to demonstrate that the Components meet the requirements of this document prior to their acceptance for installation into EIC UHV systems.

1.1 Background

The EIC Project will design, build, and install the accelerator hardware for a new electron storage ring, an electron injector, and modifications to the hadron ring required to produce an electron ion collider and infrastructure. It will include one interaction region, with an allowance for a second, and one detector. The facility is designed to meet requirements to ensure high reliability and availability for the user program.

Most of the vacuum systems in the EIC complex will be required to operate in the UHV range (<10-9 torr) in order to ensure adequate lifetime for the circulating particle beams. The absence of hydrocarbons, halocarbons and organic compounds as well as proper material selection and processing is critical to ensuring this requirement. Vacuum chambers and components which will be placed inside the vacuum system must meet stringent UHV requirements starting at the design stage and continue throughout fabrication, installation and commissioning.

2 APPLICABLE DOCUMENTS

The following specifications, standards and drawings form a part of this specification to the extent specified herein. Unless otherwise specified, the issues of these documents shall be that in effect on the date of the solicitation or contract. Exceptions must be approved in writing by BSA.

In the event of a conflict between the applicable documents and this specification, the Contractor shall immediately notify the BSA Contractual Representative who shall in each instance determine which document takes precedence and advise the Contractor accordingly. Failure to notify BSA of a document conflict shall not relieve the Contractor’s responsibility to ensure full compliance to all requirements.

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

Document Number Document Title

ASTM-

E498/E498M

Standard Practice for Leaks Using Mass Spectrometer Leak Detector or Residual Gas Analyzer in the Tracer Probe Mode

AWS D1.6 Structural Welding Code – Stainless Steel

AWS D1.2 Structural Welding Code – Aluminum

3 REQUIREMENTS

3.1 Technical/Performance Characteristics

The basic design rule for UHV Components is to minimize the gas load which will result in the lowest operating pressure with a given pumping speed. The gas load arises from surface outgassing, both thermal and desorbed, as well as gas diffusion into the system from boundary materials and leaks. The level of outgassing and desorption can vary by several orders of magnitude. The gas load is minimized by proper selection of materials, careful surface treatment, processing to reduce oils, particulates and organic matter, and by minimizing the surface area exposed to vacuum. All vacuum facing surfaces should be free of scale, stains and residues of any kind.

An important design criterion is the elimination of trapped volumes, which connect to the main vacuum through very small orifices, capillaries or material defects. Situations like these can be created by a threaded fastener, sealing weld or other fabrication processes. All volumes must be vented, either to atmosphere or to vacuum.

Vacuum sealing welds should be internal whenever possible. When this is not possible, full penetration external welds must be specified. Similarly, vacuum brazing should leave a smooth run of braze material on the vacuum side of the brazed joints. Vacuum sealing welds should always be a single weld, never a double weld. If a second strengthen weld is required, it should be a stitch or broken weld to avoid trapped volumes and allow for UHV leak detection to be carried out properly. Threaded fasteners located in blind holes inside vacuum are to be vented through a coaxial vent hole or a relief feature on the threads.

In situations when vacuum surfaces need to be coated, extreme care must be taken to avoid delaminating or peeling of the coatings. The surface to be coated must be clean and free from defects that could results in trapped volumes, particulates or contamination under the coatings. A high-temperature vacuum bake of at least 200°C is required to test the adhesion of all coatings. If an acid bath was used for plating or coating, a vacuum bake of at least 400°C shall be required unless such temperatures would damage the Component. Any evidence of peeling, bubbling or other defects in the plating will be cause for rejection.

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Cleanliness of the components is important at all times. Frequent cleaning of items before, during, and after manufacturing processes may be required. Care should be taken not to cross-contaminate "clean" and "dirty" components.

Proper support of the Components during fabrication, processing and evaluation shall be considered at the design stage to eliminate the possibility of distortion and damaging of the Components. All Components must be designed to safely withstand the loading exerted by atmospheric pressure while under vacuum. Modular Components utilizing bellows or geometries which result in differential loading while under vacuum must include proper restraints that prevent lateral and axial movements due to the differential pressure loading.

3.2 Materials

Only UHV-compatible metal and ceramic materials shall be selected for fabrication of the Components for the EIC UHV systems. Some UHV materials may be excluded based on the specific application, e.g., magnetic permeability, temperature limitation, or radiation resistance.

The Vendor is to supply material certification traceable to its original sources for each batch of material used, including material specification, chemical analysis report, mechanical properties, etc.

3.2.1 UHV Compatible Materials

The following list of materials are UHV compatible after proper cleaning and processing.

The list is not comprehensive and additional material can be considered after review and approval from the EIC vacuum group

• Stainless steel: ASTM 304L, 304LN, 316L, 316LN, 321, 347 and Nitronic®

Alloys. Unless otherwise specified, vacuum arc remelt (VAR) or hot-forged electron slag remelt (ESR) is required.

• Inconel® Alloys: 625, 718, 750

• Aluminum alloys: 2219, 5086, A6061-T6, A6063-T6 and ISO AlMgSi6060

• Copper: C10100 (OFE), C10200 (OF), C10700 (OFS), C11000 (ETP), C15715

(Glidcop AL-15), C15725 (Glidcop AL-25), C17000 (Be Cu), C18150 (CuCrZr)

• Titanium: Commercially pure, aircraft quality, type 50A

• Beryllium, Gold, Silver

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

• Mu Metal, Monel, Kovar

• High density and purity Alumina (>96%), Aluminum Nitride, Macor

• Glass, Sapphire, Silicon Nitride, Silicon Carbide

3.2.2 Incompatible Materials

• Vacuum grease or lubricants (such as Fomblin®)

• Zinc and zinc alloys found in bearings, silver solders

• Brass and brass components

• Cadmium and cadmium alloys found in bearings, solders and steel rust proofing

• Lead, Cesium, Mercury, Phosphorus, Potassium, Magnesium, Sodium, Selenium, Strontium, Sulfur or alloys containing these materials since possible surface segregation may occur

• Organics with high outgassing rates which tend to trap hydrocarbon contaminants and which are less radiation resistant. Use of Teflon® is specifically prohibited

• Elastomers used for O-ring seals in flanges and valves

3.3 Fabrication

3.3.1 Machining

Only water soluble machining lubricants are allowed. The use of silicone- or sulfur-based machining lubricants is prohibited. All machining is to be carefully controlled to ensure that no foreign matter is embedded in the surface of the material. The use of abrasive wheels or cloths, wire brushes, files, sand, polishing pastes, and the like is prohibited unless they are new and dedicated to the fabrication of the Component.

Scale removal, etc., shall be performed by careful hand brushing with a clean 300-series stainless steel brush. All Components shall be deburred prior to welding to ensure proper fit at assembly, and to prevent a handling hazard from sharp edges and burrs.

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3.3.2 Cleaning

All parts must be chemically cleaned and/or vacuum baked prior to welding, assembly, and testing. The cleaning process shall remove residual surface contaminants such as dirt, grease, oils, etc. without etching the vacuum side of the surface. Therefore, the cleaning process shall not include strong acid or alkaline etching. Mechanical operations to remove surface stains shall be kept to an absolute minimum. Any metal brushing, sand blasting, or other harsh abrasives on the vacuum side are prohibited.

The exact cleaning process depends on materials, sizes of the Components, and available Vendor facilities. The Vendor is required to specify in detail its cleaning process including detergents, solvents and chemical baths to BSA for review and approval. A copy of the EIC cleaning procedure may be requested by the contractor for reference.

Components shall be carefully inspected so that any areas which might form potential contamination traps (e.g., blind holes, crevices, or cracks) are identified to ensure that they are properly cleaned out. Edge welded bellows shall be cleaned while fixed in the extended position to minimize the risk of trapping cleaning detergents.

The recommended cleaning process shall include mild detergent washing baths with ultrasonic agitator, deionized water rinsing bath, and air or nitrogen drying oven. Non-invasive cleaning detergents, such as mildetch alkaline (e.g., Almeco 18, Ridoline 357) or acid (e.g., Citranox) solution are permissible.

After cleaning, all Components shall be handled in accordance with their intended use in a UHV system. Vacuum surfaces shall not be touched with bare hands and clean, lint and powder free gloves shall be worn during handling. All Components shall be wrapped in lint-free paper, and then tightly wrapped in vacuum-grade aluminum foil. Other package methods may be acceptable but require review and approval by BNL.

Any tools, inspection gages, fixtures or similar. which come in contact with the cleaned Components shall be cleaned to the level as the Component to prevent cross contamination.

When the tools and fixtures are not in use, they shall be covered and stored to prevent their use on dirty parts. Once contaminated, the item will need to be recleaned. Tools shall not be made of materials which could contaminate the cleaned Components, e.g., brass, plastic, zinc, etc.

Work bench surfaces shall be thoroughly cleaned with detergent, rinsed with water, and then wiped with alcohol before their use in the assembly area. The surfaces shall be hard and non-absorbent (stainless steel, Formica, etc.). Wood bench tops or similar materials are not acceptable.

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

Any wipes or cleaning cloths coming into contact with the Component must be lint free.

Spot cleaning with the use of acetone is acceptable but requires an additional wipe down with isopropyl or ethyl alcohol.

3.3.3 Welding and Brazing

The welding and brazing zones shall be free of scales, voids, micro cracks, pits, inclusions and any other type of defects. Welding shall be performed in accordance with AWS D1.6 (or equivalent) for stainless steel or AWS D1.2 (or equivalent) for aluminum. In order to guarantee that the welding zone is free of contamination, all parts shall be cleaned 48 hours prior to welding or brazing. Parts are to be protected from any contaminants before, during and after the weld operations and shall be handled with UHV approved gloves. To protect the weld zone from oxidization, parts shall be flushed with inert gas until they have cooled down to a temperature of 60 ºC or below.

All welding and brazing shall be performed in a clean area. Clean, lint-free gloves shall always be worn. All jigs, fixtures, and heat sinks shall be clean. Only clean 300-series stainless steel hand brushes are to be used for removing oxides from welds. Power driven brushes, abrasive papers and abrasive wheels shall not be used. Special care must be taken to avoid damage of vacuum sealing surfaces when removing oxidizes.

Components shall be welded using Tungsten Inert Gas (TIG), Electron Beam (EBW) or Laser Beam (LBW) welds unless otherwise specified on the drawing or accompanying specification. Unless otherwise indicated on the drawing, all vacuum welds are to be made on the "vacuum side" of the component. When external vacuum welds are specified, the welds shall have 100% penetration and the inside of the chambers shall be purged with Argon throughout the welding operation, and cool down of the weld. Where high strength requires welding on both sides of thick sections, the side facing the vacuum is to be continuous and the opposite side intermittent. At no time should there be continuous welds on both sides of the joint.

The weld zones shall be free from scale, voids, blow holes, etc. There shall be no visible evidence of inclusions. Welds inspection with X-ray or other non-invasive methods is permissible. The use of dye penetrate testing after welding is strictly prohibited. No repair of defective welds is allowed without prior approval from BSA. There shall be no machining or cleaning operations after welding without prior approval in writing from BSA

Hydrogen or vacuum furnace brazing are acceptable joining techniques for UHV Components. All brazing joints shall have adequate filler metal to provide a flush, smooth fillet free from voids, blow holes, etc., and there shall be no visible evidence of inclusion.

No silver soldered or soft soldered joints are permitted unless specified on applicable drawings.

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No welds, brazes, or joints of any kind shall bridge water or helium cooling channels and vacuum spaces.

3.3.4 Assembly

Assembly, welding, inspection, and packaging of the Components shall take place in dedicated clean areas. The areas shall not be located near machine tools, compressors, oily or dirty parts and tools, etc., which can contaminate the work area with hydrocarbons and dirt. No eating, drinking, or smoking shall be permitted in these clean areas. Unless the Components are being actively worked on or inspected, the Components shall be wrapped in clean vacuum grade aluminum foil and kept covered.

Cleaned Components shall only be handled with clean, lint and powder free gloves. Clean gloves shall only contact clean parts and tools in the clean work area. If they touch unclean surfaces (hair, face, chair, floor, tools, etc.) they shall be replaced with clean gloves. It is required that the arms or bodies of the workers which may come in to contact with the Components shall be covered with a lab coat with elastic-cuffed sleeves, to prevent debris from falling into the Components.

Prior to leaving the clean work area, Components must be properly packaged to prevent contamination. This can be accomplished by wrapping the Component in clean vacuum grade aluminum foil or a sealed container.

3.4 Marking and Serialization

All Components shall be marked in accordance with the applicable drawing, specification, SOW or Purchase Order. When permanent marking is required, the Component shall be marked dry scribing, engraving or laser. Acid etching or marker pen on any vacuum facing surface is strictly prohibited. Adhesive backed labels on any surface of the Component are not allowed.

Some Components will require serialization which will be indicated on the applicable drawing, specification, SOW or Purchase Order. Serial numbers must be unique and used for traceability of any tests performed on the Component.

The marking location, information and serial number format must be agreed upon between BNL and the contractor prior to marking.

3.5 Packaging/Shipping

The Components shall be packaged individually suitable to their dimensions and intended application. Any water in cooling channels must be completely removed and blown dry with dry nitrogen. Components shall be wrapped in lint-free paper or vacuum-grade aluminum foil and put into a clean transparent polyethylene bag. Knife-edge flanges and

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00 other vacuum-sealing faces shall be protected to prevent damage during transit and handling.

The Components must be properly supported and contained to prevent damage and contamination during transit. Durable material, such as clean wood, bubble wraps, or similar non-contaminating materials are to be used to support and protect the Components from one another during transit and storage. No peanut-type material shall be used for packaging.

Additional packing requirements may be identified in the applicable specification or SOW for the Component.

4 VERIFICATION

Appropriate inspection/tests shall be performed to ensure the Component conforms to all requirements in section 3 of this specification. The classification of inspections required will be defined by the applicable drawing, specification, SOW or Purchase Order. These inspections may include Preproduction Tests (First Article) as well as Acceptance Testing both at the factory as well as at BNL.

The inspection and testing requirements will vary depending on the type of Component being fabricated. The tests which need to be performed are specified on the associated drawing, specification, SOW or Purchase Order. Acceptance tests shall be performed on all Components prior to delivery. At a minimum, a Certificate of Compliance confirming all of the requirements defined in the associated drawing or specification is required.

BNL reserves the right to perform any of the required tests on the Component, at BNL’s expense and facilities, for verifying full compliance with the contract. Evidence of noncompliance with any of the requirements shall constitute cause for rejection.

4.1 Dimensional Inspection

Dimension inspection and allowable tolerancing shall be defined by the applicable drawings or specification. The Component shall be measured in the unconstrained state and at room temperature (68-74°F [20-23.3°C]). The inspection shall also include visual inspection for any dents, damage, poor workmanship, repaired weld. In addition, the cleanliness the Component shall be evaluated and reported.

An inspection report confirming dimensional compliance will be provided with the delivery of the Component. Reported dimensions will be in the same units as the applicable drawing or specification. If dual units are used in the applicable documentation, either format will be acceptable.

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00

4.2 Leak Test

Component assemblies require a leak check in accordance with ASTM-E498/E498M to ensure the integrity of the interfaces between separate parts. Unless otherwise specified, the Components shall have a total leak rate < 2x10-10 std.cc/sec He, as measured with a helium mass spectrometer with minimum sensitivity <lx10-10 std.cc/sec He. This mass spectrometer shall be calibrated by checking the measured leak rate against a calibrated standard.

The leak test shall be carried out in a clean area. A vacuum bakeout prior to leak checking is recommended, to drive out any cleaning solution, machining fluids, or water vapor that might otherwise plug a leak. The leak test shall be carried out with internal vacuum of < 1x10-4 torr while the leak check zone is immersed in one atmosphere helium. All-metal manifolds and valves shall connect the Components and the test equipment. Viton O-rings may be used as temporary seals for the leak test. No lubricants or greases of any kind are to be used on the O-ring seals. Greases or oil are prohibited on any internal or external surfaces, which could block the leak passage.

The leak test of the Components shall be performed with a turbomolecular pump backed by oil-free dry mechanical pump, or other UHV equivalent pumps. After leak testing, the Components shall be vented to atmospheric pressure with dry nitrogen from an evaporated liquid source or from a high-purity nitrogen bottle. A suitable leak test certificate shall be prepared for each Component.

4.3 Bakeout

Bakeout of Components shall be carried out by heating parts in a vacuum oven or by using the Component itself when possible. If a vacuum oven is not used, for example when processing a vacuum chamber, the Component shall be pumped by a turbomolecular pump backed by an oil-free dry mechanical pump, or other UHV equivalent pump. Parts which are not permanently joined together cannot be temporarily assembled for the bake out process.

The bakeout time and temperature depends on the material and shall be specified on the drawing, specification, SOW or Purchase Order of the Component. The ramp rates of the bake out shall be 50°C/hr. unless otherwise specified to protect the Component from damage resulting from excessive thermal stress. Proper temperature control of +/- 5°C is required for the bakeout process. Components must be able to withstand the maximum bakeout temperature for a minimum of 48 hours.

The bakeout process shall not be started until the pressure of the vacuum oven or internal volume of the Component is below 1x10-5 torr. The pumping system used for the bakeout must be capable of reaching 1x10-8 torr or lower by the end of the bakeout process. The bakeout is considered successful when the system returns to room

Specification Title: Design and Fabrication of Components for use in the EIC Vacuum System Revision: 00 temperature and pressure is ≤ 1x10-8 torr. The base pressure of the system will be recorded and provided with delivery of the Component. After completing the bakeout the vacuum system shall be gradually vented with dry nitrogen.

4.4 RGA Test

Components which require measurement of the residual gas composition after bakeout shall be measured using a quadrupole mass spectrometer with sensitivity down to 10-12 torr partial pressures and a range from 1-100 atomic mass units (AMU). The instrument must have a secondary electron multiplier (SEM) as well as a Faraday cup. The test shall be performed when the pressure is <5 x10-9 torr.

In order to achieve the required test pressure, it is recommended that the Component is isolated from mechanical pumps (Turbomolecular pump) with an all metal valve to prevent back streaming. This will require the introduction of a ‘closed’ UHV capture pump such as a sputtering ion (IP), non-evaporable getter (NEG) or cryopump to maintain the required test pressure.

Tested Components shall exhibit no traces of HCl, oils or other contaminants with atomic mass of 35 or greater than 40 amu with the exception of 44 when tested using a residual gas analyzer. The predominant gas component shall be hydrogen and be at least 90% of the total pressure after under vacuum for 100 hours. Total of all Masses greater than 28 amu shall be less than 10% of the total pressure. The sum of peak heights at mass locations 39, 41, 43, 45, and greater shall be less than 1% of the total pressure.

A test report shall be provided with the delivery of the Component. The report shall include the total pressure of the system during the test as well as the recorded partial pressures from 1-100 AMU shown in log scale from 1x10-8 torr down to 1 x 10-12 torr.

The plot can be shown as an analog trace or as a histogram.

After completing the RGA test, the vacuum system shall be gradually vented with dry nitrogen.