PHENIX FVTX Mechanical

1
PHENIX FVTX Mechanical
Los Alamos National Laboratory Fermi National
Accelerator Laboratory Columbia
University By HYTEC FVTX Mechanical Team August
28, 2006
2
PHENIX VTX Installed on Support Beams
Mounting Rails
Barrel Mounts
FVTX
VTX
Isolation System Stand
3
FVTX Mechanical Contents

• FVTX Points of Contact
• Introduction to HYTEC PHENIX Work
• VTX Design Overview and FY06 RD
• FY07 FVTX and iFVTX Tasks and Schedule
• Impact of VTX Design on FVTX/iFVTX
• Assembly Plan with Conceptual Fixtures

4
1. FVTX Points of Contact
1. Walt Sondheim is the primary interface to
HYTEC for all work. 2. Walt will be supported by
Dave Lee, Melynda Brooks, and Gerd Kunde. 3. Dick
Martin is the project manager at HYTEC. 4. Dick
is supported by a team of engineers and designers
including Tim Thompson, Vince Stephens, and Roger
Smith.
5
2. Introduction to HYTEC PHENIX Work

• HYTEC is responsible for VTX, FVTX, and iFVTX
  structural and cooling system designs.
• As such HYTEC will work closely with all of the
  stakeholders via our points of contact.
• 3. Commonality, synergy, and cost-effectiveness
  in the structural and cooling systems will be
  exploited wherever possible.
• 4. The sooner you give us your geometry and
  specifications, the better chance we have of
  schedule success.
• 5. Our VTX work is scheduled for completion by
  8-14-09.

6
DRAFT
RD
Conceptual and Preliminary Design
Prototyping and Drawings
Fabrication and Assembly
7
PHENIX VTX Mechanical Goals
In general, the goals for the PHENIX Silicon
Vertex Detector (VTX) mechanical project are to
design and fabricate the support structures for
the barrel and FVTX regions, isolation system,
routing of cables and utilities, electronics
cooling system, and dry gas enclosure. All of
this must integrate successfully into the VTX
system on time and within budget.
8
Mechanical Design Requirements
1. The dimensional structural stability (DSS) for
the detectors is 25 mm. 2. The gravitational
structural stability (GSS) for the entire VTX is
100 mm. 3. The structure will be designed with
natural frequencies above 70 Hz. 4. A radiation
length (RL) limit of 1 for each detector layer
will be maintained. 5. GrE and C-C materials will
be used throughout. 6. The VTX, FVTX, and iFVTX
will be actively cooled to an average temperature
of 0 oC.
9
Design Methodology
1. For each task, we go through the following
stages CDR, PDR, Prototype, FDR, Fabrication,
Assembly, Test. 2. We have the following tasks
Pixels, Strips, Support Structure, Tooling (and
Fixtures), and Environmental Systems (Cooling and
Gas). 3. We fabricate the structure using best
commercial practices. We achieve precision in
location using fixtures to establish hard
points. 4. This is the quickest, most
cost-effective approach. 5. Our largest
uncertainty is the cost of fabrication in FY09
(without having vendor quotes), but experience
helps.
10
3. VTX Design Overview and FY06 RD
During FY06 HYTEC has worked on four VTX tasks
for BNL. 1. Barrel ladder staves 2. Ladder
coolant tubes 3. Barrel mounts 4. Space
Frame As work in these RD areas progressed
during FY06, the CAD model has been improved and
updated with help from BNL and LANL. In addition,
of necessity, HYTEC has done conceptual work on
assembly fixtures and assembly procedures.
11
PHENIX VTX Detector Close-Up
12
(No Transcript)
13
Barrel Mounts
1. There are a total of 12 barrel mounts in our
current design, three on each side of each barrel
region half. 2. We have shape and thickness
concepts as shown, but we expect these to change
as a result of analysis and design
optimization. 3. We will have a preliminary
design after additional analysis at the system
level in FY07.
14
(No Transcript)
15
VTX Barrel Region Showing Window Blind Overlap
for Pixel Staves and Stair Step Overlap for Strip
Staves
16
Space Frame
1. The VTX space frame is conceptually connected
to the support rails. 2. The shape will be round
with optimized cut-outs. 3. The fabrication
technique will be to form on a mandrel and cut
out the openings. 4. We have a concept for
joining the two halves with overlapping tabs,
precision locating pins, and fasteners to lock
the connection. 5. Space frame FEM calculations
will be completed by September 15.
17
Gas Enclosure Removed to Show Space Frame and End
Electronics
18
Space and Shape Considerations for Cabling
Kapton Cu/Al Bus
Kapton Extender Cables
Pixel Layers. Each ladder 16 pixel sensors per
ladder. 5 ladders on layer 1. 10 ladders layer
2. There is one cooling tube per ladder.
19
Pixel Ladder Assembly
20
Pixel Ladder Cross-Section
21
Barrel Ladder Staves
1. These are fragile and will require careful
handling. 2. The structural analysis is
complete. 3. Dimensions have been specified. 4.
The materials will be chosen soon. 5. We are
obtaining options for filler material. 6. The
stave mounting concept may change. 7. All will be
complete and in the model by 9/30.
Exploded View of Pixel Ladder
22
Modeling Assumptions

• Model as four components
• Sensors (orange)
• Lump bus, sensor, and R/O chip as silicon block
• Thermal plane (gray)
• Cooling tube (blue)
• Omega piece (purple)
• Adhesive layer not modeled, thin small
  deflection
• FEM uses solid elements (18295 elements)
• Properties
• Dimensions

23
Stave Boundary Conditions

• Idealized boundary conditions for analysis
• Pinned (123)
• Fixed (123456)
• Axial release (12456)
• Transverse translation (12)
• Actual boundary conditions will be determined by
  spaceframe
• Spaceframe can be explicitly modeled as design
  matures

24
Results Part 1

• Hand calculations
• Looked at ½ and double of baseline values.
• Frequency and 1G deflection meet requirements for
  all parameters!
• FEM
• Focus on thermal distortion
• Results are sensitive to boundary conditions
• Selected distortion figures shown

fixed
12456
Case 1 Exaggerated by 1000xs
fixed
pinned
Case 3 Exaggerated by 500xs
Case 4 Exaggerated by 200xs
pinned
pinned
25
Results Part 2

• FEM Results

• Frequency and 1 G deflection easily meet
  requirements
• Frequency predicted from 224 to 527 Hz (expect
  closer to 527)
• 1 G deflection predicted from 1.2 to 5.9 microns
  (expect closer to 1.2)
• Thermal distortion highly dependent on boundary
  conditions
• Include moment constraint at both ends of stave
• Moment release results in large deflections (72.1
  or 244.1 microns)
• Moment constraint results in smaller deflection
  (12.9 or 25.7 microns)
• Allow stave axial growth
• Axial constraint predicts large reaction force of
  approx 20 lbs
• Axial deflection predicted between 12.9 and 25.7
  microns

26
Thermal Distortion

• Driven by large CTE of aluminum
• Standalone tube predicted to contract 125 microns
  axially.
• As part of stave, aluminum causes axial and
  bending deformations
• Ways to reduce thermal distortion
• Reduce amount of aluminum
• Reduce tube thickness, tube diameter
• In progress, determined by thermal analysis and
  manufacturing
• Increase omega stiffness
• Bound with M55J Uni, 15Msi ? 75 Msi
• Increase thickness, trade off with radiation
  length
• Replace aluminum with lower CTE material

27
Electronics Cooling Regions
1. VTX barrel ladders 2. FVTX 3. iFVTX 4.
Electronic disk regions (on ends with Spiro
boards).
28
VTX Barrel Ladder Cooling Concepts
1. Choose suitable coolant that will not boil,
that is, with sufficient pressure margin on its
saturation p versus T curve. 2. Pick a
non-aqueous coolant. 3. Adequate local heat
removal. 4. Appropriate tube size. 5. Manifold
with uniform distribution. 6. Sufficient pumping
and supply cooling capacity.
29
Desired Coolant Properties

• High thermal conductivity
• Maintains thermal/fluid properties at low
  temperatures
• Non-corrosive
• Good dielectric properties (non-conducting)
• Environmentally safe and safe to handle
• Compatible with materials selected for the
  cooling system
• Single-phase at operating temperatures

30
Cooling Fluid Comparisons
31
VTX Stave Electronics Cooling Tubing

• Aluminum 3003 Tubing
• Thermal conductivity of 111
• Has 3.9 mm outer diameter, and 0.4 mm wall
  thickness.
• With this size of diameter, coolant has an
  acceptable ?T and ?P through the length of the
  tube.
• The tube ends may be flared to help maintain a
  leak-free connection between aluminum and soft
  tubing.

Al 3003
PEEK

7.1 mm
3.1mm
1.6 mm
0.4 mm (Not to scale)

• PEEK (Soft) Tubing
• High resistance to chemicals and radiation.
• Located external of sensor region.

32
Pixel Stave Coolant Tubes, Terminations, and Tests

• HYTEC has performed a series of lab tests to
  determine the best means of connecting our
  aluminum stave tubes to the soft distribution
  tubes.
• The tests utilized aluminum 3003 tubing and PTFE
  soft tubing.
• These tests will be repeated with other types of
  tubing, and the best connection method will be
  selected for the cooling system.

33
VTX Barrel Pixel Stave Cooling
Analyses performed to date consist of hand
calculations using Mathcad and Excel. We have
also developed an FEM model of the stave lay-up
using COSMOSM. The mesh and preliminary results
are shown later.
1. Axial temperature rise with coolant mass flow
rate. 2. Coolant tube size requirements. 3. Axial
pressure drop with tube diameter. 4. Effect of
Reynolds number. 5. Total pixel heat removal
requirement. 6. Total pixel tube major pressure
losses. 7. Cooling path forward.
34
Axial Temperature Rise and Delta P as a Function
of Mass Flow Rate and Diameter
Pressure Drop vs Tube Inner Diameter
Temperature Rise vs Mass Flow Rate
35
VTX Barrel Ladder Pixel StaveCooling Conclusions
1. Things look good for the pixel stave
cooling. 2. We can control the stave axial delta
T to between 3 and 6 deg C if we flow C5F12 from
4 to 2 g/s in each tube. 3. At 2 g/s the Reynolds
number is well above 2000. 4. For a 3.2 mm inner
diameter tube, the bulk velocity will be from
about 15 to 30 cm/s. 5. The total mass flow rate
for 118 tubes _at_ 3 g/s/tube is about 354 g/s or
about 13.3 L/min for C5F12, removing about 1.1 kW
of heat. 6. The major losses (pressure drops) in
the tubes is quite small per tube but sums to
about 3.5 psi.
36
Pixel Stave Thermal Model FEM Mesh
37
Pixel Stave Temperature Field
38
Preliminary Cooling Utility Concepts
39
Ladder Coolant Tubes
1. We have departed from the in-series concept
shown on the left. 2. Analysis shows adequate
electronics cooling with a single fluid pass per
stave. 3. Tube dimensions have been specified and
samples obtained for testing. 4. The materials
will be chosen soon. 5. Our coolant will be 3M
Novec 7000 6. Detailed tests of tubing
connections are underway. 7. All will be complete
and in the model by 9/30.
40
New Cooling Utility Manifold Concept
Manifolds
41
4. FY07 FVTXTasks and Schedule
1. FVTX mounting system design using GrE and
insuring compliance with DSS and GSS. 2. Cool
eight planes of silicon disks (detectors and
electronics) to 0 oC. 3. Management and
integration. 4. A preliminary design package will
be completed by the end of FY07 (September 30,
2007).
42
5. Impact of VTX Design on FVTX

• The FVTX structural supports will be integrated
  into the structural supports for the VTX.
• For the four disks, we are close in Z, and know
  the inner and outer radii, but not the location
  of the electronics.
• 3. There are space issues for placement of the
  electronics, routing of the electronics cables
  and cooling lines.
• 4. A single cooling system will provide coolant
  to the VTX, FVTX, and iFVTX as required for
  active cooling.
• 5. FNAL is modifying a chip that may yield a heat
  load of only 100 W per arm for the sensors and
  ROCs.

43
(No Transcript)
44
PHENIX FVTX Cage Support Structure
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
(No Transcript)
51
(No Transcript)
52
(No Transcript)
53
(No Transcript)
54
FY07 iFVTXTasks and Schedule
1. iFVTX mounting system design using GrE and
insuring compliance with DSS and GSS. 2. Insure
compatibility of the iFVTX mounting system with
the FVTX detector supports. 3. Cool the silicon
detector electronics to 0 oC. 4. Management and
integration. 5. Detailed final drawings will be
produced by the end of FY07 that will enable
fabrication of the iFVTX components.
55
Impact of VTX Design on iFVTX
1. The iFVTX structural supports will be
integrated into the structural supports for the
FVTX, that is, into one half of one of the FVTX
cages. 2. A single cooling system will provide
coolant to the VTX, FVTX, and iFVTX as required
for active cooling. 3. The space issues for the
iFVTX electronics cables are not yet
determined. 4. The space issues for the iFVTX
cooling utility tubing are also not yet
determined.
56
6. Assembly Planwith Conceptual Fixtures
57
Fixtures for Loading Staves
58
Fixtures for Attaching the Space Frame to The
Barrels
Attachment Tabs