6dF Fibre Attrition Rates

1
6dF Fibre Attrition Rates

• Rachel Campbell Macquarie University
• Supervisor Quentin Parker
• With thanks to
• Kristen Fiegert, Ken Russel, Malcolm Hartley
  Donna Burton

2
Talk Outline

• Introduction
• No. of Fibres vs Time
• Fibre Breakages
• Time Between Fibre Repair
• Fibre Breakages vs Position
• Attrition Rate
• Final Questions

3
Introduction

• 6dF Spectrograph was commissioned during first
  half of 2001.
• From 9th July 2001 a database has been maintained
  by the observers
• In the past 4 years, there have been 435
  instances of a fibre being unavailable or broken

4
Available Fibres vs Time
Plate 1
150 130 110 90 70
Number of Fibres Available
2005
2002
2003
2004
150 130 110 90 70
Plate 2
5
Fibre Breakages
80 60 40 20
Plate 1
Number of Fibres
0 1 2 3 4
80 60 40 20
Plate 2
6
Time Between Fibre Repairs
50 40 30 20 10 0
Plate 1
Number of Fibres
0 1 2 3 4 5 6 7 8 9
10 11 12
50 40 30 20 10
Plate 2
7
Broken Fibre Location
Plate 1
8
Broken Fibre Location
Coverage
Plate 1
68 70 72 74 76 78 80 82 84 86 88 90 92

9
Broken Fibre Location
Plate 2
10
Broken Fibre Location
Coverage
Plate 2
68 70 72 74 76 78 80 82 84 86 88 90 92

11
Important Numbers
Schmidt telescope carries out an average of 100
observing hours/lunation or 4500 observing
hours to date. Thus
1 6dF fibre breaks every 10 observing hours