March 7, 2007 CLAS12 Drift Chamber Review Mac Mestayer CLAS12 Drift Chamber Construction - Mac Mestayer Technical Details of Construction —buy endplates

March 7, 2007 CLAS12 Drift Chamber Review Mac Mestayer

CLAS12 Drift Chamber Construction-Mac Mestayer

Technical Details of Construction—buy endplates —build “box”—insert feedthroughs—string chambers

• Cost and Schedule


CLAS12 Drift Chambers

Design: same concept as present chambers:NIM A449(2000)81

•6 sectors, 3 regions•18 drift chambers•24192 sense wires

drift chambers


Endplates: many precise holes

Number of Holes4925 feedthrough holes12 survey 3 datum & alignment28 bolt & attachment

1.7 m

First Order Placed-due back in March-large, modern milling machine


Endplate Details

0.200 mmtrue position “50 m”


Endplates fit into Frames

Receive endplates- inspect- measure hole positions- clean- shim- bolt and glue into frames


Chamber Ready to String

Box Assembledendplates attachedattachment brackets affixed

Next ---- mount on stringing fixture- insert feedthroughs- pre-tension- string wires- attach circuit boards- QA/QC


CLAS12 Stringing Fixture


Parts: wire circuit board

conductive rubber

circuit board

crimp pin

feedthrough

endplate

signal routing:wires pre-amp

wire


Stringing wires between “slanted” endplates

endplates

“gravity” stringingwires: 9 cm - 4 m longwires strung individuallywires attached by crimpingwires positioned by “trumpet”


Steps in Stringing


Installing Pre-tensioning Wires

Pre-tensioning- before we start stringing- use springs on guard wires- gradual release of tension


Stringing the Chamber


Bussing Field Wires

Bussing Field Wires- under the circuit board- gold-plated copper wire- one “miscellaneous part”- e.g. 16,000 ft. - $6000

- do this before mountingcircuit boards


Project Overview & Responsibilities

• Oversight: Jefferson Lab

• Design & BuildRegion 1: ODURegion 2: JLabRegion 3: Idaho State

• Prototypingfull-sized Reg. 1 prototype: Jlab, ODUplastic vs. metal-tipped feedthroughs: Jlab,

ODU, ISU


Drift Chamber Schedule

PED


CLAS12 Drift Chamber PED

test prototype this summer


Drift Chamber Construction Schedule

3 YEARS


Details: Stringing the Chambers

~2 yrs./ 6 chambers

~1/2 time for stringing


• Estimate the time; use labor cost tables

• “Bottoms-up” estimate - based on previous experience2 people, 15 mins. per wire for stringing“stringing” per se takes 1/3 to 1/2 of the time3 crews of 5 stringers for ~ 2 years3 - 4 techs / scientists doing support, QA/QC

• “Top-down” - simple scaling of total elapsed time, accounting for fewer wires

Costs: Stringing the Chambers


CLAS12 Drift Chamber Procurements/Expenses

Forward Tracker Procurements and Expenses (K$)

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stringing labor- estimate time- use labor rate


CLAS12 Drift Chamber: Construction Costs

Forward Tracker

Proj.

Sub-tasks MT ET ME EE MD ED VU S US Proj man-wks k$Design chamber 21 10 21 21 36 1 110 135 135

Buy Endplates 690 1 3 7 5 3 6 25 29 719

Wires, pins, feedthroughs 380 1 2 4 5 3 6 21 23 403

Misc. parts 200 2 4 5 5 4 9 29 32 232

Box assembly 400 16 8 8 40 9 22 103 101 501

Design stringing fixture 9 2 9 6 26 44 44

Build stringer 50 10 2 35 3 9 59 49 99

String chamber 1791 56 6 150 40 130 4 386 298 2,089

Design stb/hvtb 15 15 45 15 100 190 159 159

Buy stb/hvtb 325 10 1 5 2 10 28 29 354

Mount stb/hvtb 10 10 40 2 24 2 6 84 95 105

Total $3,846 126 65 37 18 54 50 264 108 334 5 1061 $994 $4,840

PED 30 15 12 15 30 45 0 42 136 1 326 $338 $338

CONSTRUCTION $3,846 96 50 25 3 24 5 264 66 198 4 735 $656 $4,502

Total (k$)

Total Labor

Labor (man-weeks)

Outside Costs

Techs. Engrs. Designers Scientists

PED: 0.34 M$Const: 4.50 M$

Total: 4.84 M$


CLAS12 Drift Chambers: Cost

• Same concept as present CLAS chambers• Small extrapolations from current designs

smaller cells, thicker wire, faster gas• Cost estimates based on prior experience

180$ / sense wire : mechanical costsmajor cost is “wire-stringing”re-use most electronics

• Schedule and manpower allocation: prior experience

• Experts on staff and in CLAS collaboration


• Phenix DC’s (“jet-cell” type with 36 super-modules)Mechanical costs:

• $250/sense wire (but 7-8 other wires per sense wire)• $50/total wire

• CLEO-c DC’s (“open-cell” with “square” cells)Mechanical costs:

• $40/total wire (labor not included)

• CLAS12 DC’s (“open-cell” with hexagonal cells)Mechanical costs:

• $180/sense wire• $49/total wire (labor included)

Cost Comparison: Other Drift Chambers


• “Harder to do”Region 1: 7.5 mm cell; 1.8 m long wire

• Easier to do”smaller chambers

• 7 m endplate 4 m endplate

chambers are flat • stereo wires are all parallel

sense wire: 20 m 30 m • less breakage, easier to see !

Risks: Stringing the Chambers


CLAS Drift Chambers : History

• Operating successfully for ~10 years ….


CLAS Drift Chambers : History

…. with good resolution

• mid-cell resolution is 200 - 250 m

• whole-cell average: 310, 315, 380 m; for R1, R2, R3

…. at the same voltage, with same efficiency Ar/CO2 shows no

conventional aging


Conclusions

Large project: 18 chambers, 90K total wires

Reliable design: should achieve resolution and efficiency

goals

Low risk cost and schedule: based on detailed knowledge from CLAS

High probability of success: experienced people


• Broken wiresmore extensive “shake-down”better temperature control (already

implemented)• Circuit board corrosion

go to encapsulated SIP’s better humidity control (partially implemented)finer segmentation (partially implemented)

• High current drawstricter irradiation procedures (already

implemented)better humidity control (partially implemented)more HV channels (planned for near-term)

Operational Problems & Solutions


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CLAS12 / CLAS costs (not labor)

rati

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task

CLAS12 DC’s have 70% as many wires

Some tasks don’t depend on wire count


Forward Tracker Labor (man-weeks)

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CLAS12 Drift Chambers : Labor

task

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PED tasks


Methods of Cost Estimation

Endplates: cost = (a + b * nwires) * inflation; a = .2, b = .8

“boxes”: cost = old cost * 0.75 * inflationWires, pins, feedthroughs; cost = old_cost *

wire_ratio * inflation


Recent cost estimates (06/-07)

• Recent Estimates from Tom Hartlove (with backup documents)• Region I endplates, 12ea, @ $36K (quote from Master Machine)• Region II endplates, 12ea, @ $50.6K (machined, quote from

Stesalit)• Region III endplates, 12ea, @41.6K (machined, quote from Martel

Marine)• Region I inserts, reduced tolerances, 80K parts @ $6.2K

(~$0.08/part) (quote from 4slide)• Field wire, 140um Al, 106km @ $94.9K (~$0.9/m)(quote from

CFW)• Sense wire, 20um Tungsten, 40km @$27.7K (~$0.69/m)(quote

from CFW, probably cheaper from Luma)• DC Wire Setup charges, $135/2000ft. i.e. fresh die every 2k ft.

(quote from CFW)• Region I crimp pins, 70K parts @ $95.2K (~$1.36/part)(quote

from Medelec)• Conductive rubber tubing, 100 ft @ $330 (quote from Chomerics)• Prototype HV boards 6 ea. @ $1120 (quote from Accurate Circuit)


Possible Sources of Cost-Saving

• use “angle-iron” for chamber framespros: won’t warp, much cheapercons: need fixture to assemble full frame

• increase tolerance: stainless-steel “trumpets”pros: can find a willing vendorcons: may not be as accurate or take longer

to accept


Detailed CLAS Costs from P.O.’s

• Region II• Endplates, 12ea. @ $30K/plate,

$420K• Installer, $24.5K• Stringing booms, $3K• Scaffolding, $3.8K• Attachment parts, $27K• Trapezoid, $9.5K• Strongback, $4.8K• U-channels, $3K• Posts, $11.2K• Crane for cleanroom, $4.6K• Cable supports, $20K• Misc. stringing stuff, $13K• Inserts, 125K parts, @ $ 19.6K• Crimp pins, 125K parts, @ $19.3K• Feedthroughs, 125K parts, @

$17.5K•

•

Region I Boss Ring, $10k Prototype chamber, $49.5K Finite element analysis, $13.1K Additional prototyping costs, $9.2K Helmholtz coils, $14K Transport cart, $5K Endplates, 12 ea. @ $50K Procure feedthrough assemblies, etc. $75K Procure parts, fabricate 6 chambers, $250K


Original Detailed CLAS Costs from P.O.’s

• WIRE, all regions combined.• Sense, 20um Tungsten, 118 km, $15.5K (~$0.13/m)• Field, 140um Aluminum, 344 km, $357.1k (~$1.04/m)• Guard, No records found.• Bus wire, $7K• • Region III• Skin connectors, $61.8K• Skins, $234.9K• Endplate material and machining, $400.2K• Closure bars, $70.2K• Hole inspection, $5K• Alignment fixture materials, $17K• Stringing platform, $36.3K• Chamber to Torus mounting posts, $72K• Eagle claws, $8K• Transporter, $6K• U-channels, $3K• Inserts, 110K parts @ $31.3K (~$0.29/part) + additional parts from inferior

vendor• Feedthroughs, 122K parts @ $54K (~$0.44/part)• Crimp pins, 152K parts @ $34.3K (~$0.23/part)• Plastic plugs for rubber connectors, $0.9K• Rubber connectors, $15K (approx.)


On-chamber electronics - 310K$ estimate

Signal Translator Boards -- Board Only

R1_STB QTY # Sectors Totals Cost Each Total $

Layer 1 7 6 42 $315.00 $13,230.00

Layer 2 7 6 42 $315.00 $13,230.00

R2_STB QTY # Sectors

Layer 1 7 6 42 $335.00 $14,070.00

Layer 2 7 6 42 $335.00 $14,070.00


Layer 1 7 6 42 $375.00 $15,750.00

Layer 2 7 6 42 $375.00 $15,750.00

252 $86,100.00

STB Components Per Board Board Mult Total QTY Cost Each

HV Capacitors 110 252 27720 $1.25 $34,650.00

PreAmp 96 252 24192 $3.00 $72,576.00

Regulator 16 252 4032 $1.65 $6,652.80

Power Connector 1 252 252 $1.75 $441.00

Output Connector 6 252 1512 $3.15 $4,762.80

Resistors 20 252 5040 $0.05 $252.00

Capacitors 20 252 5040 $0.05 $252.00

$119,586.60


High Voltage Boards

R1_HVB QTY # Sectors Totals Cost Each Total $

Layer 1 7 6 42 $125.00 $5,250.00

Layer 2 7 6 42 $125.00 $5,250.00

R2_HVB QTY # Sectors

Layer 1 7 6 42 $125.00 $5,250.00

Layer 2 7 6 42 $125.00 $5,250.00

R3_HVB QTY # Sectors

Layer 1 7 6 42 $200.00 $8,400.00

Layer 2 7 6 42 $200.00 $8,400.00

$37,800.00

HVB Components Per Board Board Mult Total QTY Cost Each

HV Capacitors 10 252 2520 $1.25 $3,150.00

Resistors 110 252 27720 $0.05 $1,386.00

Solder Posts 16 252 4032 $0.25 $1,008.00

$5,544.00


LOW VOLTAGE CABLE

R1_STB QTY # Sectors Totals Cost/Ft Length(Ft) Total $

Layer 1 7 6 42 $1.25 6 $315.00

Layer 2 7 6 42 $1.25 6 $315.00

Cable Connectors 28 6 168 $1.50 $252.00


Layer 1 7 6 42 $1.25 7 $367.50

Layer 2 7 6 42 $1.25 7 $367.50



Layer 1 7 6 42 $1.25 8 $420.00

Layer 2 7 6 42 $1.25 8 $420.00


$2,961.00

HIGH VOLTAGE CABLE


Layer 1 7 6 42 $3.00 6 $756.00

Layer 2 7 6 42 $3.00 6 $756.00



Layer 1 7 6 42 $3.00 7 $882.00

Layer 2 7 6 42 $3.00 7 $882.00



Layer 1 7 6 42 $3.00 8 $1,008.00

Layer 2 7 6 42 $3.00 8 $1,008.00


$6,552.00


PreAmp Output Cables -- (0.025" Pitch)


Layer 1 42 6 252 $4.00 6 $6,048.00

Layer 2 42 6 252 $4.00 6 $6,048.00

Cable Connectors 168 6 1008 $3.15 $3,175.20


Layer 1 42 6 252 $4.00 7 $7,056.00

Layer 2 42 6 252 $4.00 7 $7,056.00



Layer 1 42 6 252 $4.00 8 $8,064.00

Layer 2 42 6 252 $4.00 8 $8,064.00


$51,861.60

Documents

March 7, 2007 CLAS12 Drift Chamber Review Mac Mestayer CLAS12 Drift Chamber Construction - Mac Mestayer Technical Details of Construction —buy endplates