feb ’02, trt meetings jack fowler – duke university sem analysis of wire from aging test #5 jack...

Feb ’02, TRT MeetingsJack Fowler – Duke University

SEM Analysis of Wire from Aging Test #5

Jack Fowler

Feb ’02, TRT MeetingsJack Fowler, Duke HEP

Module Test Layout


Wire Samples Analyzed

Xe-CO2 gas volume Wire 11 – Production wire with glass encapsulated joint Wire 12 – Production wire with glass encapsulated joint Wire 14 – Production wire with glass joint

Xe-CF4-CO2 gas volume Wire 16 – Production wire with glass encapsulated joint Wire 18 - Production wire with glass encapsulated joint Wire 20 – Pre Series 1 (.3 to .4 m) with PEEK joint Wire 24 - Production wire with glass encapsulated joint

Wire analysis Performed at Analytical Instrumentation Facility at North Carolina State University


Wire 11 Segment 1

Very small pores Fine scratches No deposits


Wire 11 Segment 3



Wire 11 Segment 4



Wire 11 Segment 5

Very small pores More scratches,

these are probably made during production

No deposits


Wire 11 Segment 5 Close up

Medium size pores ~0.25 m, more densely populated than upstream

No deposits Grain boundary

very defined


Wire 12 Segment 5

Very small pores One large scratch

that does not appear to have compromised the wire

No deposits


Wire 12 Segment 6

Very small pores Many scratches,

probably made in production

No deposits


Wire 12 Segment 6 Close Up

Very small pores Fine scratches,

wire has not been compromised

No deposits


Wire 12 Segment 7

Very small pores Few scratches No deposits Some surface

contamination



Very small pores Small scratch No deposits Defect in gold

plating does not appear to have enlarged


Wire 24 Segment 1

Very small pores One large scratch

along top surface No deposits


Wire 24 Segment 2

Very small pores One scratch along

center, appears the same as the rest of the surface

Some small white deposits


Wire 24 Segment 3

Many pores of all sizes

Surface is covered with deposits, analysis indicates they are Au



Note how the deposits seem to be in clusters

Again the elemental analysis indicates only Au


Wire 24 Segment 4 in CWS

Wire appears very clean and undamaged


Wire 24 Segment 4 beside CWS

Wire surface appears smooth

Many large white deposits.

These show up as Au, C, O and F.


Wire 24 Segment 4 Surface Analysis

This is the elemental analysis of the dark areas around the deposits

Note the C and F peaks. The C is greater than the F.


Wire 24 Segment 4 Surface Analysis

This is a elemental analysis of the white deposits

Note the C and F peaks have become equal



Here is a close up of the gold damage


Wire 24 Segment 4 Epoxy

This shows the region where the epoxy meets the wire.

The epoxy is covered with deposits


Wire 24 Segment 4 Epoxy Surface Analysis

Note the large F and C peaks on the surface of the Epoxy.

Note also the absence of Au


Wire 24 Segment 5


Surface is covered with deposits, the analysis indicated Au

Also note dark appearance of surface




Note the grain boundaries have lost their definition


Wire 24 Segment 6


Surface is covered with deposits, Au only


Wire 16 Segment 6

Note that the large scratch does not appear to have been damaged more than the rest of the surface


Wire 24 Segment 7


Surface deposits have drastically reduced




Note the pores occur on the grain boundaries

Surface deposits have drastically reduced


Wire 20 Segment 1

Surface appears normal

Light scratches No deposits


Wire 20 Segment 3

Wire is still in good condition

Fine pores No scratches No deposits


Wire 20 Segment 4

Heavy damage of gold plating

Large deposits Analysis indicates

the deposits are mainly Au


Wire 20 Segment 4

Heavy damage to wire


Wire 20 Segment 4

Wire coming out of wire joint

Surface of the wire shows heavy deposits

The PEEK appears undamaged


Wire 20 Segment 5

Many pores Heavy deposits These deposits

contained Au and W


Summary

It is clear that the wire is damaged Xe-CO2 wire only exhibit small pores on surface

Xe-CF4-CO2 wires show heavy damage, both Au removal and deposits

It appears that the damage increases in the high radiation areas and as you move downstream in the straw

Thicker Au plating protects the wire longer There is fluorine detected on the surface of the wire We detected no silicon on the surface


To Do

Inspect incoming wire for pores We have never seen these pores on unused wire

Confirmation of the test results This should be done when IU gets their test results

Evaluate the possibility of water being trapped on surface, that may accelerate the damage

Evaluate differences from earlier tests


Thin Plating Comparison


What are the Deposits? Si or Au


Surface Damage

feb ’02, trt meetings jack fowler – duke university sem analysis of wire from aging test #5 jack...

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