SEM Analysis of Wire from Aging Test

1
SEM Analysis of Wire from Aging Test 7 atDuke
University

Jack Fowler
2
Module Test Layout
3
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

4
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

5
Wire 19 Glass Encapsulated Wire joint

• Gas Volume - Xe-CO2 -CF4
• Current - 16.6 ?A
• Charge 2.4 to 2.9 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Few deposits

6
Wire 20 Polyimide Wire Joint

• Gas Volume - Xe-CO2 -CF4
• Current - 15.4 ?A
• Charge 2.3 to 2.7 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• No visible change

7
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

8
Wire 14 Segment 5

• 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

9
Wire 14 Segment 5

• 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
• Fine Deposits are Na and Cl

10
Wire 19 Segment 4

• Gas Volume - Xe-CO2 -CF4
• 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

11
Wire 19 Segment 4

• Gas Volume - Xe-CO2 -CF4
• 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

12
Wire 19 Segment 5

• Gas Volume - Xe-CO2 -CF4
• 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

13
Wire 19 Segment 5

• Gas Volume - Xe-CO2 -CF4
• 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

14
Wire 20 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide 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
• Gold etching and removal

15
Wire 20 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide 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
• Gold etching and removal
• Again loss of surface definition

16
Wire 20 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current - 15.4 ?A
• Charge 2.3 to 2.7 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Area show at 2 kV beam energy

17
Wire 20 Segment 5

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current - 15.4 ?A
• Charge 2.3 to 2.7 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Surface is covered with deposits

18
Wire 20 Segment 5

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current - 15.4 ?A
• Charge 2.3 to 2.7 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Pores in surface
• Faint grain boundaries still present
• Deposits are mainly Au

19
Wire 20 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current - 15.4 ?A
• Charge 2.3 to 2.7 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Discolored region near wire joint 700 ?m

20
Wire 20 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current - 15.4 ?A
• Charge 2.3 to 2.7 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Here is the section where the transition occurs

21
Wire 20 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current - 15.4 ?A
• Charge 2.3 to 2.7 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Very heavy gold damage
• This affect was seen on both sides of the wire
  joint.

22
Wire 22 Segment 4

• Gas Volume - Xe-CO2 -CF4
• 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

23
Wire 22 Segment 4

• Gas Volume - Xe-CO2 -CF4
• 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

24
Wire 22 Segment 5

• Gas Volume - Xe-CO2 -CF4
• 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 and islands

25
Wire 22 Segment 5

• Gas Volume - Xe-CO2 -CF4
• 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

26
Wire 23 Segment 3

• Gas Volume - Xe-CO2 -CF4
• 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

27
Wire 23 Segment 3

• Gas Volume - Xe-CO2 -CF4
• 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

28
Wire 23 Segment 4

• Gas Volume - Xe-CO2 -CF4
• 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

29
Wire 23 Segment 5

• Gas Volume - Xe-CO2 -CF4
• 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

30
Wire 31 Segment 4

• Wire - thin plated preseries
• Gas Volume - Xe-CO2 -CF4
• Current - 8.9 ?A
• Charge 1.2 to 1.5 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Large pores
• Heavy gold damage

31
Wire 31 Segment 7

• Wire - thin plated preseries
• This region was visibly darkened during removal
• Gas Volume - Xe-CO2 -CF4
• Current - 8.9 ?A
• Charge 1.2 to 1.5 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Small deposits

32
Wire 31 Segment 7

• Wire - thin plated preseries
• This region was visibly darkened during removal
• Gas Volume - Xe-CO2 -CF4
• Current - 8.9 ?A
• Charge 1.2 to 1.5 C/cm
• Exposed Time 1680 hrs
• Target Flow Rate 15cc/hr
• Small deposits of F

33
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

34
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

35
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 and Pores
• Fine white deposits

36
IU Wire 2 Segment 4

• 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

37
IU Wire 2 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.4 ?A
• Charge 3.3 C/cm
• Exposed Time 672 hrs
• Target Flow Rate 15 cc/hr
• Few pores
• Good surface grain definition

38
IU Wire 2 Segment 7

• 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
• More C deposits than in earlier segments

39
IU Wire 2 Segment 7

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.4 ?A
• Charge 3.3 C/cm
• Exposed Time 672 hrs
• Target Flow Rate 15 cc/hr
• More C deposits than in earlier segments
• Loss of grain definition from segment 4

40
IU Wire 18 Segment 4

• Gas Volume - Xe-CO2 -CF4
• No Wire Joint
• Current 1.7?A
• Charge 2.4 C/cm
• Exposed Time 408 hrs
• Target Flow Rate 15 cc/hr
• Large C deposits

41
IU Wire 18 Segment 5

• Gas Volume - Xe-CO2 -CF4
• No Wire Joint
• Current 1.7?A
• Charge 2.4 C/cm
• Exposed Time 408 hrs
• Target Flow Rate 15 cc/hr
• Large C deposits
• Some large pores

42
IU Wire 18 Segment 5

• Gas Volume - Xe-CO2 -CF4
• No Wire Joint
• Current 1.7?A
• Charge 2.4 C/cm
• Exposed Time 408 hrs
• Target Flow Rate 15 cc/hr
• Some loss of grain definition

43
IU Wire 19 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• 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

44
IU Wire 19 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• Charge 4.0 C/cm
• Exposed Time 672 hrs
• Target Flow Rate 15 cc/hr
• Slight decrease in grain definition
• Some small pores

45
IU Wire 19 Segment 5

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• Charge 4.0 C/cm
• Exposed Time 672 hrs
• Target Flow Rate 15 cc/hr
• Surface has many small C deposits
• Some porosity

46
IU Wire 19 Segment 5

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• Charge 4.0 C/cm
• Exposed Time 672 hrs
• Target Flow Rate 15 cc/hr
• Small pores around grain boundaries
• Some porosity

47
IU Wire 39 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• Charge 4.9 C/cm
• Exposed Time 816 hrs
• Target Flow Rate 15 cc/hr
• Surface smooth in appearance
• Many large C deposits

48
IU Wire 39 Segment 4

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• Charge 4.9 C/cm
• Exposed Time 816 hrs
• Target Flow Rate 15 cc/hr
• Many C deposits
• Loss of grain definition

49
IU Wire 39 Segment 5

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• Charge 4.9 C/cm
• Exposed Time 816 hrs
• Target Flow Rate 15 cc/hr
• Surface smooth in appearance
• Large C deposits

50
IU Wire 39 Segment 5

• Gas Volume - Xe-CO2 -CF4
• Polyimide Wire Joint
• Current 1.7?A
• Charge 4.9 C/cm
• Exposed Time 816 hrs
• Target Flow Rate 15 cc/hr
• Surface is smoother
• Less grain definition
• C deposits

51
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 gt 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