ESD No. 1.3-134 Revision 1 Page 2 of 14 fileESD No. 1.3-134 Revision 1 Page 4 of 14 Author(s): Nanyang Li Date: July 05, 2007 2.0 MATERIAL 2.1 Core Material 2.1.1 Steel The core shall

ESD No. 1.3-134 Revision 1 Page 2 of 14

Author(s): Nanyang Li Date: July 05, 2007

1.0 INTRODUCTION The Linac Coherent Light Source (LCLS) project at the Stanford Linear Accelerator Center

(SLAC) is intended to create a free electron laser source of 1.5 Å x-ray pulses of unprecedented brightness and short time duration. At the end of the electron beam line, the electrons will be steered downward by three Beam Dump vertical dipole (1.69VD55.1) magnets described in this specification. These magnets will be used in DC mode.

1.1 Scope of the Specification This specification outlines the minimum requirements governing the fabrication and testing of the components and assembly of LCLS 1.69VD55.1 magnet. This specification further outlines the minimum requirements for packaging and shipping the completed and tested magnet and coils from the vender site to SLAC.

1.2 Scope of Work The vender shall fabricate three 1.69VD55.1 magnets plus 1 set of coils (2 coils) as per drawings listed in section 1.3 and the provisions written in this specification. The vender shall conduct the inspections, tests and measurements as per descriptions in this specification as a minimum. The vender shall develop machining, assembling and test procedures, quality assurance (QA) procedures and test documentation (travelers) and shall record all pertinent production information and test records. The vender shall pack and ship completed magnets and coils to SLAC as per requirements described in this specification and procurement terms and conditions.

1.3 Design Drawings Drawings shown are major assembly drawings, detail drawings are listed in appropriate title blocks and will be provided by SLAC.

SA380-328-01 1.69VD55.1 BYD Magnet Assembly SA380-328-02 1.69VD55.1 BYD Magnet Half Assy-A SA380-328-03 1.69VD55.1 BYD Core Half SA380-328-04 1.69VD55.1 BYD Magnet Half Assy-B SA380-328-20 1.69VD55.1 BYD Coil Assembly PF380-328-30 1.69VD55.1 BYD Lamination Standard PF380-328-25 1.69VD55.1 BYD Lamination End Front PF380-328-26 1.69VD55.1 BYD Lamination End Back PF380-328-31 1.69VD55.1 BYD Lamination Support



1.4 Magnet Design Parameters

Parameter Value

Magnet Max. Design Central Field (Tesla) 1.2214

Magnet Operation Central Field (Tesla) 0.9286

Dipole QTY 3

Magnet Design Effective Length (m) 1.452

Magnet Gap (m) 0.044

Max. String Power (kW) 24.8

Max. String Voltage (v) 82

System Water Drop ∆P (psi) 60

System Allowed Temperature Rise ∆T ºC 13

Coil Turns 72

Coil Number per Pole 1

Conductor Size 0.44x0.44/ID0.186/0.055R (11.176mm sq x 4.724mm hole)

Water Circuits per Magnet 8

Max. Design Current Density amp/mm2 3

Design Coil Resistance at 40ºC (µΩ) 45.0224

Design Magnet Resistance at 40ºC (Ω) 0.0900

Max. Design Magnet Current (Amp) 303

Magnet Operation Current (Amp) 230

Max. Design Magnet Power (watt) 8267

Max. Design Magnet Voltage (v) 27.28

Design Water Flow per Circuit (gpm) 0.36

Design Magnet Water Flow (gpm) 2.85 Magnetic Field Quality Requirement Value

Good Field Region (mm) ±35

Effective Length Variation of 3 magnet < 2x10-3

Integral Field Uniformity∫∫

Β

∆Β

dl

dl in good field < ±1x10-2

Multipoles n≥2 @r=10mm ≤ 5x10-4



2.0 MATERIAL

2.1 Core Material

2.1.1 Steel

The core shall be made from solid steel of AISI 1010 low carbon steel. The properties of the steel, including chemical components and ferromagnetic character, that the vender purchases shall be supplied to SLAC.

2.1.2 Anneal

To ensure good magnetic properties, the purchased steel shall be annealed before delivering, otherwise, the core laminations including end plates shall be annealed after rough machining following a standard annealing cycle. The following cycle is the one that SLAC recommends for AISI 1010.

Fill Oven with a dry reducing atmosphere. ACTIVITY TIME 1. Place laminations in an oven which is at any temperature below 1000°F 2. Heat oven at 400°F/ hour up to 1200°F 0.5- 3 3. Wait 2 hours at 1200°F 2 4. Heat oven from 1200°F to 1400°F at 100°F/hour 2 5. Hold at 1400°F for a period for all laminations to reach 1400°F Approx. 1 6. Hold at 1400°F for one MORE hour 1 7. Leave laminations in oven, cool oven at 150°F/hr down to 1100 °F 2 8. Leave laminations in oven, cool oven at 200°F/hr down to 500 °F 3 9. Remove laminations from oven and air cool down to room temp Approx. 12

2.2 Coil Conductor The copper conductor for building coils will be supplied by SLAC, the cross dimension is 0.44”x0.44” with 0.186” ID hole and 0.055” corner radius. The continuous length of one reel supplied by SLAC is about 256 ft, which is sufficient for one pan cake winding that is about 210 ft conductor length.

2.3 Coil Insulation Material 2.3.1 Turn to Turn Insulation

Mylar Tape 0.75” wide x 0.0033” thick

Woven Dacron Tape 0.75” wide x 0.005” thick

2.3.2 Ground Wrap Insulation

Woven Fiberglass Tape 1.5” wide x 0.01” thick



2.3.3 Fillers

The voids in spaces between the ground wrapped coil and potting mold must be filled with glass cloth, glass roving or NEMA G-10 cut pieces. Pure epoxy filler(s) is not allowed, because of significant difference of shrinking ratio with cupper during the cooling cycle.

2.3.4 Impregnation Formulation

The following is a description of the formulation recommended by SLAC. It shall be used to vacuum impregnate 1.69VD55.1 magnet coils.

Element Vendor Parts by Weight

i. Resin Epoxy DER 332 Dow Chemical Co. 45 Epoxy DER 732 Freeport, TX (both) 55

ii. Hardener NMA Shell Chemical 90-96 BDMA Shell Chemical 1.0-1.5

iii. Wetting Additive Dow Corning Corp. Z6040 Midland, Mich 1.0

iv. Filler Tabular Alumina, Alcoa T61-325-1, Low Iron 224

v. CAB-0-SIL Cobot Corp. 3.75

125 High St. Boston, MA

vi. Curing Cycle Pre-cure for 8 hours minimum after coil has reached 75°C±5°C. Post-cure for 4 hours after coil has reached 120°C.

2.4 Coil Lead Block and Buss OFHC copper shall be used to build the coil lead crossover block and buss.

2.5 Braze Rod Cu to Cu brazing rod BCup-5 (15% Ag, 5%P and 80% Cu) shall be used for water /power crossover block to coil lead welding.

2.6 Mechanical Fasteners All fasteners shall adhere to US standards for size and strength.

2.7 Hydraulic Circuits Hoses and water fittings shall use US standards in callout of SLAC drawings. Water manifold shall be fabricated by 304 passivated stainless steel or equivalent.



2.8 Seal Material Teflon tape is NOT allowed for water fitting joins. Loctite PST shall be used for joints sealing purpose.

2.9 Klixon Switch SLAC will supply thermal switches and wire. The switches shall be tested before installation.

3.0 FABRICATION

3.1 Coil Fabrication Each coil shall be identified with a unique number. This number shall be temporarily attached to the coil with a tag during the production and shall be stenciled to the final surface in permanent ink or paint at the leading end of the coil. The number shall be from 01 to 08 and with prefix: “LCLS 1.69VD55.1”.

3.1.1 Coil Winding Preparation

3.1.1.1 Environment

Coils winding and storage area shall be free of metallic chips, dirt, and welding or chemical fumes.

3.1.1.2 Conductor Preparation

Conductors shall be cleaned with alcohol using clean and lint free cloth before applying turn-to-turn insulation while winding. One length of conductor shall be used for each pan cake winding. Internal splices shall not be allowed in finished windings.

3.1.2 Pan Cake Winding The conductor shall be pulled with sufficient tension during winding to minimize keystone at tight bends. The conductor shall be “set” after each bend and meet the dimensions called in the drawing.

3.1.3 Coil Ground Insulation

Four (4) pan cakes shall be wrapped into one piece coil, by ground insulation tape.

3.1.4 Coil Impregnation

Ground wrapped coil shall be potted in a vacuum potting mold with the epoxy formulation specified in 2.3.4 (or University approved equivalent). The final coil dimensions of completed coil shall meet those shown in the drawing.

3.1.4.1 Environment

Impregnation shall be performed in an area free of metallic chips, dirt, and welding or chemical fumes. Impregnation compounds and ground wrapped coils shall be protected from dirt, moisture and damage during storage and handling. Temperature of impregnation facility shall be kept at 25ο C ± 5ο C and shall be baffled to reduce excess air circulation.



3.1.4.2 Impregnation

Large voids between the ground wrapped coil and the potting mold shall be filled with the filler called for section 2.3.3. Standard procedures for vacuum impregnation shall be designed, followed and recorded. These include:

Mixing of the components at prescribed temperatures;

Vacuum de-aeration of the epoxy mixture while mixing at an elevated temperature to remove bubbles which might form at the curing temperature;

Delivery of the epoxy to the mold under vacuum and successive venting and evacuation of the filled mold to remove bubbles.

The filled mold shall be vented with suitably placed vent tubes and tipped in the curing oven to assure that bubbles can escape in these tubes. The vent tubes act like standpipes and should have sufficient fluid capacity to compensate for epoxy shrinkage in the mold during curing.

The filled mold shall be cured at prescribed temperature cycle in the oven.

3.1.4.3 Repairs

Easily accessible surface bubbles and voids and cracks shall be filled with epoxy. Internal cracks bridging over the space between adjacent conductors shall be repaired by drilling out or otherwise removing the cracked insulation and filling with epoxy. All repaired cracks and voids in the finished coils shall be noted and described in the travelers which accompany each coil.

3.1.5 Brazing The copper thermal interlock mounting plate, copper crossover block for pan cake winding to winding water and power connections shall be hard soldered to the coil leads. The winding leads shall be bent to the shape and cut to the length as outlined in coil assembly drawing SA-380-328-20. A bending fixture and cut templates must be designed and used to insure serial connected leads can be fitted into the slots in the crossover block with no compelling force. A US standard braze filler rod (BCuP-5) requested in section 2.5 shall be used for brazing. The appropriate cleaning and fluxing procedure for the selected hard solder should be followed in order to guarantee a good braze joint. The area of the conductor insulated by epoxy should be suitably protected to prevent burning during brazing.

3.1.6 Water Circuit Connection

The pipe thread built in the copper crossover block and the installation of the Parker connector to the block shall follow the standard procedure of the NPT. The water hose and Swivel shall be crimped together adequately.

3.1.7 Fittings

The water fittings and seal material prescribed in section 2.7 and 2.8 shall be used for those joints between crossover block and the fittings. Installation must be done carefully in order to prevent any excess Loctite and dirt or chips from getting into the cooling channel and subsequently causing clogging in the channel. The vender shall clearly and permanently



mark “IN” and “OUT” on each crossover block to indicate water supply and water return to prevent miss-connection of water circuits.

The connection between the fitting and Synflex Swivel that is crimped on the water hose shall not use the Loctite to enhance the sealing. The built in configuration of those parts have guaranteed the appropriate sealing.

3.2. Core Fabrication Although the 1.69VD55.1 magnet will be operated under DC mode and not routinely for time-varying field, it will be cycled to accommodate operations under varying electron beam energy, therefore 1” thick lamination is selected for a short excitation period (few seconds).

3.2.1 Core Half Length

Two end plates shall not be finally ground before core stacking. The thickness of two end plates shall be adjusted during the stacking procedure until correct core length being reached.

3.2.2 Support Lamination

Two special support laminations shall be carefully located at the positions indicated in the drawing. One lamination between these two special laminations shall not be finally ground before core stacking. The thickness of this lamination shall be adjusted during the stacking procedure until correct distance between them per drawing has been reached.

3.2.3 Half Gap

The machining procedure shall be carefully selected in order to reach the 1/2 gap tolerance and thereafter the gap requirement called in the drawing.

3.2.4 Squareness

The stacking fixture shall be carefully built in order to reach the squareness of core half and maintain stacking tolerances after tie bars being welded.

3.2.5 Stacking Gap

The lamination must be machined to have gaps no greater than 0.002”/0.05mm across any mating surfaces between two laminations during stacking.

3.2.6 Identification

Each core half shall be identified with a unique number. The number shall be stamped on front end plate.

3.2.7 Weldment

The half assembly and the whole assembly of 1.69VD55.1 magnet are heavy and will be lifted either by the side tie bar or the top tie bar. Therefore the strength and secure penetration of weldment of these tie bars must be guaranteed to protect the core and coils against damage during handling and protect personnel working with these heavy elements.

3.2.8 Matching Core Half Lengths

Two core halves for a core assembly shall be selected to make the least difference of their lengths.



3.2.9 Pin Installation

Pre-assemble the core without coils. After all tolerance requirements of a core assembly being reached, bolts two core halves securely with equal torque among 9 bolts, drill and install one horizontal pin and two longitudinal pins.

3.3 Magnet Assembly 3.3.1 Magnet Assembly

The 1.69VD55.1 magnet assembly shall consist of the following main components:

1. Two (2) core halves;

2. Two (2) coils and coil supports;

3. Electrical power bussing, thermal interlock and wiring;

4. Hydraulic assembly including a supply and a return water manifold and hoses and fittings.

3.3.2 Coil Assembly

The coils shall be horizontally and longitudinally centered against core half. The coils shall be bracketed against the core securely.

3.3.3 Bus Connection

The crossover blocks and power connection flags shall be attached to the core so that their weights and buss weight are entirely carried by the core. The blocks and flags shall be electrically insulated from the core with NEMA G-10 epoxy fiberglass block, or equivalent. The buss and the power connection flag, at the least, shall have touching area no less than 85% mating contact free of force and 90% contact after torque.

3.3.4 Paint

Exposed magnet iron shall be painted with Safety BLUE Rust-Oleum industrial Choice DTM5200 water based acrylic enamel with DTM5200 Primer. The pole area, the mating area for two core halves assembling and the tooling ball sockets shall not be painted. Pole faces shall be protected with anti-rust grease before crating.

3.3.5 Identification

Each 1.69VD55.1 magnet shall be identified with a unique number. A metal name plate shall be affixed to the magnet at the position indicated on the assembly drawing. The name plate shall state:

LCLS 1.69VD55.1 – 01, or 02, 03 (Magnet serial number) Magnet Assembly Drawing Number: SA 380-328-01 Total weight of magnet in pounds: Date of completion: Manufactured by ____



4.0 QUALITY ASSURANCE, TESTING AND DOCUMENTATION

4.1 Traveler A set of inspection sheets (travelers) shall be devised by the vender. These travelers shall include pertinent records, inspection results and electrical and hydraulic test data of those main magnet components: lamination, end plate, core half, core assembly, coil and magnet assembly. The information included in the traveler shall include at minimum the following data. Component or Magnet serial number; Names of technicians/inspectors conducting the procedure/inspection and dates; Inspection results / Electrical test and measurement results / Hydraulic measurement

condition and results; Name of supervising technician approving the component / magnet and date.

The original of the completed, signed and approved traveler shall be filed at the vender site. The copies of a set of travelers for each completed magnet shall be delivered to SLAC after completion of the magnet.

4.2 Inspection and Tests The following inspections and tests shall be conducted during the fabrication and after completion of a component or a magnet in order to assure their adequate performance during operation.

4.2.1 Coil Inspection and Test

4.2.1.1 During Fabrication

Ball test

In order to verify the continuity of the cooling channel, a steel ball with 60% to 70% of the hole diameter is blown through the conductor using pressurized dry air before winding.

Visual inspection

Visual inspection of the conductor before the winding of each coil shall be performed to locate any flaw that may damage insulation tape and cause turn to turn short.

Coil dimension inspection

The coil inner and outer dimensions shall be inspected after ground wrapping to insure they meet the sizes called in the drawing and will seat in potting mold.

4.2.1.2 After Fabrication

Water leak test

Fill either water or dry gas into the water channel of completed coil at 350psi for 1 hour. No detectable pressure decrease shall be observed.

Water flow test

Flow water into completed coil with ∆P=60 psi between in and out water pressure. The reading water flow shall be no less than 5% of the design value indicated in the table of section 1.4.



Resistance measurement

The measurement shall be made with a micro-ohm meter resistance bridge at room temperature, with the coil temperature uniform throughout and steady state conditions prevailing. The resistance of each coil shall be within ±%1.5 of the average value of 8 coils.

Impulse test

Applying a short pulse of 500 voltage across a combination of capacitor and the coil being tested, observing the damped oscillatory response displayed on the oscilloscope. Raise the voltage in several increments to full voltage (1kV). The coil shall be pulsed at least ten times at full voltage. There shall be no noticeable change in frequency or damping rate during these ten tests. There shall be no “grass” on the wave form due to corona. One each picture shall be taken at 500V and 1kV respectively. These two pictures shall be attached with the traveler of the tested coil.

4.2.2 Core Half Measurement

4.2.2.1 Stacking Gap

The gap between each adjacent lamination shall be measured. The gap shall be less than 0.002”/0.05mm across the mating surface.

4.2.2.2 Core Length Measurement

The core length shall be measured at four (4) positions at the least: one at pole tip, two at back and one at the leg of the yoke.

4.2.2.3 Half Gap Measurement

Half gap shall be measured at 12 points longitudinally at the least. One at front end plate and one at back end plate, and the rest evenly spread along the core.

4.2.2.4 Flatness and Squareness Measurement

The flatness of the pole tip and leg of the yoke and the squareness of core half shall be measured.

4.2.3 Core Assembly Measurement

The gap shall be measured at 12 points longitudinally at the least. One at front end plate and one at back end plate, and the rest evenly spread along the core.

4.2.4 Completed Magnet Inspection

4.2.4.1 Resistance Test

The method described in 4.2.1.2 “Resistance measurement” for coil resistance measurement shall be used. The resistance shall be within ±%1.5 of average value of 3 magnets.

4.2.4.2 Hi-Pot Test

Applying a 1 kV DC to power lead plates with the core grounded for a minimum period of one (1) minute. The measured leakage current shall not exceed 10 µA.



4.2.4.3 Water Leak Test

Either blow dry gas or run water flow through magnet water circuits via manifolds at 350 psi, no detectable leakage shall be observed after 1 hour.

4.2.4.4 Water Flow Test

Run water through completed magnet water circuits with ∆P=60 psi between supply and return manifolds. The reading water flow shall be no less than 5% of the design value indicated in the table of section 1.4.

4.2.4.5 Thermal Switch Continuity Test

The wiring of thermal switches shall be tested for continuity.

4.3 Magnetic Field Measurements Before the measurement, the magnet shall be operated with coils at 300 amp for a period of not

less than 10 hours continuously, with 20-25ºC cooling water at a pressure drop of 60 psi. After 10 hours of continuous running, the temperature of the cooling water shall be measured at the exit and found to conform to the temperature rise specification in the table of section 1.4.

4.3.1 Measurement Contents

The vender shall perform magnetic field measurements for all three magnets. The following field properties shall be measured and the measurement results shall be attached with the travelers. Any result that exceeds the requirement listed in the table of section 1.4 of this specification shall be informed to SLAC immediately.

4.3.1.1 Effective length

The variation of effective length of three 1.69VD55.1 magnets shall be less than 2x10-3.

4.3.1.2 Field Uniformity

Integral field uniformity shall be measured in the good field region +35mm to -35mm at y=0 with an interval no bigger than 5mm. The integral field uniformity requirement is ±1x10-2.

4.3.1.3 Multipole Components

Multipole components of the field shall be calculated at r = 10mm and they shall not exceed those values required in the table of section 1.4 of this specification.

4.3.2 Measurement Currents

Field quality measurements shall be made at 230 and 303 amp respectively. Effective length shall be made at 230, 255, 280 and 303 amp.

4.3.3 Conditioning Cycle

Prior to magnetic measurements, each magnet shall be conditioned by raising the current to 110% of the maximum design current (333 amp) and returning the current to zero three times. The magnet shall stay at 333 amp for no less than 30 seconds before returning to zero to allow the magnet set up at max. current.



4.3.4 Measurement Tooling

4.3.4.1 Integral Field Measurement

A sweeping line integral coil shall be used. The coil shall be able to be operated at two modes: “uncompensated” and “compensated”. A data acquisition system serving this sweeping coil to collect the raw output and reduce the measurement data shall be used. The “uncompensated” mode of the sweeping coil shall be used to measure integral field and the “compensated” mode shall be used to measure multipole components of the field.

4.3.4.2 Hall Probe Measurement

A Hall Probe with 1.5 m longitudinal travel capability shall be used for 1.69VD55.1 magnet effective length measurement.

4.3.5 Polarity

The positive and negative signs shall be clearly marked on the power lead plates.

4.3.6 Repeatability

The vender shall repeat the measurements requested above on first 1.69VD55.1 magnet: initial assembly, and then split it apart and re-assembled. Both measurement results shall meet the requirements and the data shall be attached to the travelers of the first production magnet.

4.4 Final Inspection Upon completion of the magnetic measurements, a careful final inspection shall be carried out. This inspection shall consist of a physical inspection as well as verification that all documentation is in proper order.

4.4.1 Physical Inspection

A visual inspection shall be made of the core, coil, bussing and water connections. Procedures shall be followed to verify that all fasteners are properly torqued, the interlocks are properly seated and wiring is undamaged. All hydraulic circuits shall be thoroughly drained and dried using dry gas. Open fittings for hydraulic circuits shall be properly sealed. Unpainted core surfaces shall be checked to see that they are properly coated and protected against moisture and rust.

4.4.2 Documentation

The required documentation collected at the end of magnet assembly shall consist of the following travelers and recorded data for each magnet (total of 6 documents). Copies of all these travelers shall be mailed to SLAC separately from the magnet shipment. Originals of all travelers shall be permanently filed at the vender site.

Coil travelers (2, including 8ea pan cake winding travelers). Core traveler (1 including 2ea core half travelers). Assembly traveler (1). Magnetic field measurement data. Quality certification signed by the vender QA authority.



5.0 PACKAGING AND SHIPPING The magnet shall be seated vertically, i.e. open side of C shape is upward.

5.1 Shipping Crate No more than one magnet shall be packed in a shipping crate. The shipping crate shall be attached to a pallet so that it can be moved using standard handling devices (forklift or pallet jack). SLAC recommends using the hoist ring holes on two side tie bars of the magnet to mount the magnet to a metal frame and the frame shall be then tied to the pallet.

5.1.1 Environmental Protection

The magnet shall be covered or wrapped to protect it from moisture within the shipping crate. It shall be properly braced and cushioned within the shipping crate so that it will not shift within the crate during handling and shipment. Additional cushion or spacer shall be inserted between two coils to prevent possible vibration.

5.1.2 Packing List

A packing list shall be installed in the crate. It should contain the following information:

Identification number of the magnet being packed in the crate. Date of packing. Name of the inspector who conducts the final inspection and his/her signature.

5.2 Marking Identification of the crate, identification number of the magnet contained in the crate and the gross weight; the name of the receiver and final destination (shown as below) shall be clearly marked on the top and additionally at two sides of the shipping crate. Arrows shall be conspicuously marked on the exterior surface of the crate to indicate its upright position.

Attn: Nanyang Li 2575 Sand Hill Rd. SLAC M/S 18

Menlo Park, CA 94025 Tel: (650) 926-2252

5.3 Two (2) Coils The same standards for shipment protection and handling described for the magnet crates shall be applied. Coil leads shall be cushioned by styro-foam to prevent bending or damage. The crate shall be conspicuously marked on the outside with a description of the contents.

Documents

ESD No. 1.3-134 Revision 1 Page 2 of 14 fileESD No. 1.3-134 Revision 1 Page 4 of 14 Author(s): Nanyang Li Date: July 05, 2007 2.0 MATERIAL 2.1 Core Material 2.1.1 Steel The core shall