may’02, trt workshop jack fowler – duke university sem analysis of wire from aging test #7 at...

May’02, TRT WorkshopJack Fowler – Duke University

SEM Analysis of Wire from Aging Test #7 at

Duke University Jack Fowler

May’02, TRT WorkshopJack Fowler, Duke HEP

Module Test Layout


Duke Wire Samples Analyzed

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

Xe-CF4-CO2 gas volume Wire 19 - Production wire with glass encapsulated joint Wire 20 - Production wire with polyimide joint Wire 22 - Production wire with no joint Wire 23 - Production wire with PEEK joint Wire 31 – Pre-series wire with no wire joint

None of the wires shown were cleaned prior to installation into chamber

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


Wire 14 Glass Wire Joint

Gas Volume - Xe-CO2

Current - 14.8 A Charge ~ 2.5 to 3.0 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~

15cc/hr Light deposits of Na and

Cl


Wire 19 Glass Encapsulated Wire joint

Gas Volume - Xe-CO2 -CF4


15cc/hr Few deposits


Wire 20 Polyimide Wire Joint



15cc/hr No visible change


Wire 14 Segment 4

Gas Volume - Xe-CO2

Glass Wire Joint Current - 14.8 A Charge ~ 2.5 to 3.0 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~

15cc/hr No deposits


Wire 14 Segment 5

Gas Volume - Xe-CO2


15cc/hr


Wire 14 Segment 5

Gas Volume - Xe-CO2


15cc/hr Fine Deposits are Na and

Cl


Wire 19 Segment 4


Glass Encap Wire Joint Current - 16.6 A Charge ~ 2.4 to 2.9 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~

15cc/hr Large pores Gold etching and removal


Wire 19 Segment 4


Glass Encap Wire Joint Current - 16.6 A Charge ~ 2.4 to 2.9 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~ 15cc/hr Large pores Gold etching and removal Notice the loss of surface

definition and grain boundaries


Wire 19 Segment 5


Glass Encap Wire Joint Current - 16.6 A Charge ~ 2.4 to 2.9 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~



Wire 20 Segment 4


Polyimide Wire Joint Current - 15.4 A Charge ~ 2.3 to 2.7 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~



Wire 20 Segment 4



15cc/hr Large pores Gold etching and removal Again loss of surface

definition


Wire 20 Segment 4



15cc/hr Area show at 2 kV beam

energy


Wire 20 Segment 5



15cc/hr Surface is covered with

deposits


Wire 20 Segment 5



15cc/hr Pores in surface Faint grain boundaries still

present Deposits are mainly Au


Wire 20 Segment 4



15cc/hr Discolored region near

wire joint ~700 m


Wire 20 Segment 4



15cc/hr Here is the section where

the transition occurs


Wire 20 Segment 4



15cc/hr Very heavy gold damage This affect was seen on

both sides of the wire joint.


Wire 22 Segment 4


No Wire Joint Current - 15.4 A Charge ~ 2.3 to 2.7 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~ 15cc/hr Large pores Notice large regions where

it appears that gold surface is uneven, possibly islands removed


Wire 22 Segment 4


No Wire Joint Current - 15.4 A Charge ~ 2.3 to 2.7 C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~

15cc/hr Large pores All surfaces appear in the

same condition


Wire 22 Segment 5



15cc/hr Large pores and islands


Wire 22 Segment 5



15cc/hr Large pores


Wire 23 Segment 3


PEEK Wire Joint Current - 7.4 A Charge ~ 0.8 to 1.0C/cm Exposed Time ~ 1680 hrs Target Flow Rate ~

15cc/hr Fine deposits Grain definition is reduced


Wire 23 Segment 4





Wire 23 Segment 5





Wire 31 Segment 4

Wire - thin plated preseries



15cc/hr Large pores Heavy gold damage


Wire 31 Segment 7


This region was visibly darkened during removal



15cc/hr Small deposits


Wire 31 Segment 7


This region was visibly darkened during removal



15cc/hr Small deposits of F


IU Wire Samples Analyzed

Xe-CO2 gas volume Wire 2 – Production wire with polyimide joint

Xe-CF4-CO2 gas volume Wire 18 - Production wire with no joint Wire 19 - Production wire with polyimide joint Wire 39 - Production wire with polyimide joint

None of the wires shown were cleaned prior to installation into chamber

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


IU Wire 2 Segment 1

Gas Volume - Xe-CO2

Polyimide Wire Joint Current – 1.4 A Charge ~ 3.3 C/cm Exposed Time – 672 hrs Target Flow Rate ~15

cc/hr C deposits


IU Wire 2 Segment 1

Gas Volume - Xe-CO2


cc/hr C deposits and Pores Fine white deposits


IU Wire 2 Segment 4

Gas Volume – Xe-CO2


cc/hr C deposits


IU Wire 2 Segment 4



cc/hr Few pores Good surface grain

definition


IU Wire 2 Segment 7

Gas Volume - Xe-CO2


cc/hr More C deposits than in

earlier segments


IU Wire 2 Segment 7



cc/hr More C deposits than in

earlier segments Loss of grain definition

from segment 4


IU Wire 18 Segment 4


No Wire Joint Current – 1.7A Charge ~ 2.4 C/cm Exposed Time – 408 hrs Target Flow Rate ~15

cc/hr Large C deposits





cc/hr Large C deposits Some large pores





cc/hr Some loss of grain

definition




Polyimide Wire Joint Current – 1.7A Charge ~ 4.0 C/cm Exposed Time – 672 hrs Target Flow Rate ~15

cc/hr C deposits Some small pores Surface is smoother than

wire 18




Polyimide Wire Joint Current – 1.7A Charge ~ 4.0 C/cm Exposed Time – 672 hrs Target Flow Rate ~15 cc/hr Slight decrease in grain

definition Some small pores




Polyimide Wire Joint Current – 1.7A Charge ~4.0 C/cm Exposed Time – 672 hrs Target Flow Rate ~15

cc/hr Surface has many small C

deposits Some porosity





cc/hr Small pores around grain

boundaries Some porosity





cc/hr Surface smooth in

appearance Many large C deposits





cc/hr Many C deposits Loss of grain definition





cc/hr Surface smooth in

appearance Large C deposits





cc/hr Surface is smoother Less grain definition C deposits


Summary

It is clear that the wire is damaged in Duke wires and the surface has changed in Indiana wires

Wire damage may be more a function of time exposed to gas as opposed to the amount of accumulated charge

Duke wires have > double the exposure time IU wires have higher accumulated charge

Xe-CO2 wire only exhibit small pores on surface

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

There is trace fluorine detected on the surface of the wire

may’02, trt workshop jack fowler – duke university sem analysis of wire from aging test #7 at...

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