Title: MECO Magnet Vendor Briefing at MT18
1MECO Magnet Vendor Briefing at MT-18
October 23, 2003 Bradford A. Smith, MIT-PSFC MECO
Magnet Subsystem Manager
2Outline of Topics
- Conceptual design overview
- A few words about procurement
- Draft SOW overview
- Magnet Work Breakdown Structure (WBS)
3Conceptual Design Status
- MIT-PSFC completed in Feb02 a conceptual design
for the magnet system with a successful final
review by a national review committee. - Conceptual design effort also included a detailed
cost and schedule estimate for final design and
fabrication - CDR Chapters
1. Introduction and summary 2. Interfaces 3.
Field specs and field matching 4. Conductor
design 5. Insulation design 6. Joint design 7.
Current lead and bus bar design 8. Quench
detection system 9. Quench protection system
10. Power supplies, dump resistors and
switches 11. Structural design criteria 12. PS
system stress analysis 13. TS system stress
analysis 14. DS system stress analysis 15.
Cryogenics system design 16. Magnet assembly 17.
Magnet installation
Available http//meco.ps.uci.edu/MIT_MECO_CDR.pd
f
4System Overview
29,000 kg 28,000 kg
53,000 kg
53,000 kg
5Magnet Interfaces
- Current magnet interface information is available
by WBS at - http//meco.ps.uci.edu/ref_design/ref_design.html
6Field Requirements
- Magnetic field varies more or less monotonically
from 5 T at the high field end of the PS to 1 T
at the low field end of the DS. - Field matching is required over a curvilinear
cylindrical volume around the magnet axes as
defined by a detailed specification.
Field specification characteristics
7Field Solution Method
- Postulate a set of n coils, coil builds and
ampere-turns that might meet the field
requirements. - Calculate fields at n points and influence
coefficients for each coil at each point. - Calculate the field contributed by the iron.
- Compare the field at n points against the field
required by the specification. - Invert the influence coefficient matrix to obtain
a corrected set of ampere-turns for each coil. - Check the field against the spec along three
paths. - Iterate as required.
- Final iteration and field calculation done with
actual conductors, NI and builds
Field specification paths
8Field Solution
- A system of 94 solenoids, some with generally
similar axial extent, but generally different
radial builds meet the field requirement. - Coils are powered in 6 sets
- PS 3500 A
- TS13u 1500 A
- TS2 4000 A
- TS3d5 1500 A
- TS4 4000 A
- DS 4000 A
- Conductor placement tolerance study indicated
maximum current limits for TS and DS coils.
- TS Straight sections 1500 A
- TS Bends 4000 A
- DS 4000 A
9Conductors 1
- MECO has permission to draw from existing
inventories of SSC inner and outer cable
- Conceptual design focused on and succeeded in
achieving a design with acceptable margins using
SSC cables
10Conductors 2
- Design guidelines
- Fraction of critical ? 0.65 (will be revised to
? 0.4), and - Temperature Margin ? 1.5 K
- SSC cables will be soldered into half-hard copper
channels to meet protection guidelines (Max V 2
kV, Max T 150 K). - PS is subject to nuclear heat load
Coil boundary (1st PS coil)
He
He
Contours of constant temperature margin in high
field PS coil
11Conductors 3
PS 3500 A
- Current limited by nuclear heating and
temperature margin - 41 km of SSC Inner Cable (includes 25 overage)
- fc 0.31
- Bmax 5.9 T
TS 1500 4000 A
- Current limited by conductor placement tolerances
- 30 km of SSC Outer Cable (includes 25 overage)
- fc 0.12, 0.28 respectively
- Bmax 3.5, 2.8 T, respectively
DS 4000 A
- Current limited by conductor placement tolerances
- 30 km of SSC Outer Cable (includes 25 overage)
- fc 0.26
- Bmax 2.03 T
12Electrical Joints
- Joints are lap solder joints
- Joints must meet the same margin requirements as
the conductor
- Fraction of critical current ? 0.65 (? 0.4
when updated) - Temperature Margin ? 1.5 K
- Conceptual design showed these margins can be
achieved with the proper choice of solders and
overlap lengths - Channel solder 60Sn-40Pb
- Hands solder 44In-42Sn-14Cd (Indalloy 8)
- Overlap length 2 cable twist pitches (19 cm)
13Insulation
- Turn ground insulation is epoxy impregnated
- Turn insulation
- 1-mil, half-lapped Kapton 3 mil, half-lapped
fiberglass (S-glass in PS) - Voltage stress is about 10 V/mil on dump, max.
for combined thickness - Ground insulation
- Turn insulation plus 40 mil (1 mm) of fiberglass
(S-glass in PS) - Voltage stress is about 40 V/mil on dump
- PS Insulation must be designed to withstand
nominal 30 Mrad - Radiation level is not significant for insulation
compressive or shear strength. - Gas evolution deserves to be minimized.
- Industrial study by Cryogenic Materials, Inc.
recommended an epoxy system with the following
components and cure - DGEBF resin, 90 ppw, Vatico (Ciba Geigy) GY282
- PPGDGE toughener, 10 ppw, Dow Chemical DER 732
- DETD hardener, 26 ppw, Vantico (Ciba Geigy)
HY5200 - Gel at 90 C for 15 hours
- Cure at 130 C for 15 hours
14Quench Detection and Protection
- Because all coil inductances are generally not
alike, a digital quench detection system is
proposed. - Each coil and coil-coil joint is voltage tapped.
- In addition, all coil currents are monitored and
dI/dt values are calculated. - System calibration is performed at installation
during charge and discharge. - External dump minimizes helium loss and recovery
times - MIT quench code (SOLQUENCH) has been run on the
highest field coils in each of the PS, TS and DS
temperature distributions are output to ANSYS for
structural analysis.
- Maximum hot spot temperature and maximum voltage
requirements are met, while stresses and
temperatures remain below allowables.
15Structural Design and Criteria
Overview
- MECO magnet system is divided into 4 magnet
assemblies, each with its own cryostat PS, TSu,
TSd, and DS. - Division is based on shipping limitations and
natural boundaries formed by each magnets
function. - Loads between assemblies are reacted through
their respective cold mass supports to the
facility foundation. - Any or all coil groups may be energized
- Warm bores may be at atmosphere or vacuum
Design criteria
- Combination of fusion and ASME criteria are used
for guidance in coil structural design. - Fusion criteria allow primary membrane stress to
be based on the lesser of 2/3 Yield (Sy) or ½
Ultimate (Su) when coils are supported by cases. - Otherwise ASME code criteria are used
- Bases primary stress on 1/3 Su
- Bending discontinuity and secondary stresses
- Bolting and column buckling guidance is taken
from AISC - Sy and Su are taken at the loaded temperature
16Coil Structures
- Production Solenoid (epoxy impregnated coils,
bath cooled)
- Outer Al shells provide hoop load support
- Spherical-end rods take TS attractive loads
- He can designed for 5 atm (quench)
- Transport Solenoid (epoxy impregnated,
conduction cooled)
- Coils are wound outside H-shaped SS mandrels
- Horizontal V formed by spherical-end-rod pair
restricts horizontal motion at Be window - Mid-span rod reacts centering load and is
designed for tension only - Vertical V spans proton beam port, provides
lateral restraint and assists with gravity load
- Detector Solenoid (epoxy impregnated, conduction
cooled)
- Uses spherical-end rods and H-shaped SS mandrels
like TS
17Cryostats and Cryogenics
All cryostats have stainless steel vacuum shells
and LN2-cooled thermal radiation shields.
- Production solenoid
- Natural convection/force-cooled with 6700 liter
LHe volume to safely remove 192 W of nuclear heat
load at 4.5 K - 25 cm diameter quench vent stack keeps quench
pressure below 5 atmospheres - Transport and detector solenoids
- Lack of nuclear heat load enables conduction
cooling - Inner and outer copper shells intercept radiation
heat load and take it to He-traced copper heat
sinks at the top of each coil
18Cryogenic Heat Loads
Supports
8.0
Valves
2.99
Vacuum separators
0.86
Therma
l radiation from 80 K
3.28
High energy radiation
192
Conductor electrical joints (qty 10)
1.24
Current leads
11.2
PS dewar
1.3
GRAND TOTALS
269.31
61.8
19Cryogenic Flow Diagram
- Current plan is to purchase a new
refrigerator/liquefier to a spec developed by the
magnet Vendor. - System is designed to be flexible and accommodate
all modes of operation
20Conclusions on Conceptual Design
- Feasibility has been demonstrated.
- Review (February 2002) was successful.
- Led to further specific industrial studies that
have been completed to reduce risk. - Insulation study
- Refrigerator/liquefier study
- Winding and impregnation approach
- Magnet Tech Spec and SOW for procurement is being
drafted. - Safety review studies have been initiated at BNL.
- Results from Conceptual Design, Industrial and
Safety Studies will be integrated into the Magnet
Technical Specification and SOW for Final Design,
Manufacturing, Installation and Commissioning.
21A Few Words about Procurement
- Draft RFP
- Based on draft technical and interface
requirements. - Will be used to initiate response from industry
- Contracting terms
- Need for clarification
- Final RFP
- Based on final technical and interface
requirements - Clarified technical and contractual requirements.
22Draft SOW - Overview
- Items furnished by MECO project
- SSC cable
- General Responsibilities of the Vendor
- Deliverables with the proposal
- Final design
- Fabrication
- Installation
- Acceptance test
- Reporting
23General Responsibilities of the Vendor
- The Vendor shall, unless otherwise noted, furnish
all labor, materials, equipment and facilities to
design, fabricate, assemble, install and test the
MECO magnet system in accordance with the
SOW/spec document. - Magnet system conductor, coils, cold structure,
cryostats, cold-to-warm and warm supports, PS and
DS iron returns, bus and leads, control dewars,
power supplies, quench detection and protection
systems, cryogenic valves and piping, cryostat
vacuum equipment, instrumentation and controls - Installation/acceptance test site Brookhaven
National Laboratory - The Vendor shall supply all documentation
required in the specification.
24Preliminary Magnet WBS
25PS Magnet WBS (Lower Level Sample)