MRO Delay Line ICD - University of Cambridge

Metrology System to Beam Combining Facility ICD INT-406-VEN-0012 v0.4.doc
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MRO Delay Line ICD
Metrology System to Beam Combining Facility
ICD INT-406-VEN-0012
The Cambridge Delay Line Team
rev 0.4
5 October 2009
Cavendish Laboratory
JJ Thomson Avenue
Cambridge CB3 0HE
UK
Metrology System to Beam Combining Facility ICD INT-406-VEN-0012 v0.4.doc
1
ICD Description
ICD
Number
INT-406VEN-0012
2
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Sub-systems
Org
Owner
Metrology BCF
System
UoC
MF
Brief description and preliminary
contents
Relates metrology bench, services and
electronics racks etc to BCF (BCA)
area.
• Location and requirements of
metrology bench
• Location and requirements of
electronics racks
• Service connections, heat removal
etc.
Change Record
Revision Date
Authors Changes
0.1
2007-08-10
MF
First draft version
0.2
2009-05-20
MF
Major revision to account for choice of Agilent laser. Details of
modules, including VME requirements and metrology cabling.
0.3
2009-06-16
MF
Revised IP module to Acromag IP470A: p6
Revised utility power requirement to metrology system: p7
Description for powering additional receiver modules added:
p8
0.4
2009-10-05
MF
Corrected optical fibre code to E1705E on page
3
Notification List
The following people should be notified by email that a new version of this document has
been issued:
MROI:
Fernando Santoro
UoC: Chris Haniff
David Buscher
Martin Fisher
2
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Table of Contents
1
2
3
4
5
6
7
8
9
ICD Description ...........................................................................................................................2
Change Record.............................................................................................................................2
Notification List ...........................................................................................................................2
Scope............................................................................................................................................3
Acronyms and Abbreviations.......................................................................................................3
Applicable Documents.................................................................................................................4
Reference Documents ..................................................................................................................4
Introduction..................................................................................................................................4
Requirements ...............................................................................................................................5
9.1
Metrology Table...................................................................................................................5
9.1.1
Metrology table area and location................................................................................5
9.1.2
Metrology table height .................................................................................................5
9.2
Electronics............................................................................................................................5
9.3
Cabling .................................................................................................................................6
9.4
Services ................................................................................................................................7
9.5
Thermal loading ...................................................................................................................7
10
Design ......................................................................................................................................7
10.1 Metrology Table...................................................................................................................7
10.2 Connections..........................................................................................................................7
10.2.1
Laser metrology ...........................................................................................................7
10.2.2
Shear Camera ...............................................................................................................8
10.2.3
Mirror mount control ...................................................................................................8
10.2.4
Grounding ....................................................................................................................8
10.3 Laser cooling........................................................................................................................9
11
Appendix..................................................................................................................................9
4
Scope
This document describes the interface requirements for the metrology system within the BCF. This
includes the size and positioning of the metrology table(s), the accommodation of electronics
associated with the metrology system, cabling requirements and services. The layout of the
metrology system on the table is not specifically part of this interface.
5
BCA
BCF
BRS
DL
DLA
ICD
ICS
SCS
Acronyms and Abbreviations
Beam Combining Area
Beam Combining Facility
Beam Relay System
Delay Line
Delay Line Area
Interface Control Document
Interferometer Control System
Supervisory Control System
MROI Magdelena Ridge Observatory
Interferometer
UoC University of Cambridge
NMT New Mexico Tech
OPD Optical Path Delay
TBC To be confirmed
TBD To be determined
3
Metrology System to Beam Combining Facility ICD INT-406-VEN-0012 v0.4.doc
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Applicable Documents
DOCUMENTS
AD1 Top Level Requirements INT-406-TSP-0002
AD2 MROI Delay Line Derived requirements INT-406-VEN-0107
DRAWINGS
AD3 MROI Beam Combining Facility
.
7
Reference Documents
RD1
Delay line to Beam Relay system (INT-406-VEN-0008)
RD2
Delay line to metrology system (INT-406-VEN-0010)
RD3
Metrology System to Beam Relay System (INT-406-VEN-0013)
RD4
Parts list for the MROI Metrology System
RD5
5517FL Laser Head User Manual
RD6
M3 Architectural Dimension Floor Plan AR101
RD7
Metrology system drawing set
RD8
Internal memo (email from T Coleman 2009-05-29)
8
Introduction
This ICD describes the facilities and services which the metrology system requires to be provided in
the BCF. There are four areas of interface: the metrology table in the inner BCA; the placement of
electronics chassis in the outer BCA; the cabling between the electronics chassis and subassemblies
on the metrology table; and the services required at the metrology table and the electronics chassis.
The size and positioning of the metrology table is closely associated with the delay lines which the
metrology system feeds (information on the interface between the delay lines and the metrology
system is contained in RD2 and the layout of the components on the metrology table is presented in
RD4). Access to the delay line end-plates close to the table and also to components on the table is
very important and since space in the inner BCA is limited some further compromise may be
necessary e.g. incorporating some of the other optical components required in the BCA on the
metrology table.
To meet heat loading limitations in the inner BCA (RD8), most of the electronics associated with
the metrology system is located in the outer BCA while the laser head, located on the metrology
table, is to be ventilated by forced air drawn in from and returned to the outer BCA.
Metrology System to Beam Combining Facility ICD INT-406-VEN-0012 v0.4.doc
9
Requirements
9.1
Metrology Table
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9.1.1 Metrology table area and location
A metrology table area of 7.2m minimum by 0.6m minimum is required to support the optical layout for 10
delay lines fed by up to two laser heads. It may comprise several tables but must behave as one monolithic
table.
Access is required to the front (closest to the delay lines) and rear of the table for adjustment of various
optical components and the shear camera. This places a maximum practical width on the optical table of
1.8m.
The distance between the end-plate of each delay line and the nearest edge of the metrology table
should not be less than 0.75m. This allows sufficient space for the protection mechanism of the DL
science beam exit window to project a further 250mm in front of the end-plate (the surface of which
is 100mm from the inside wall of the BCA) thus allowing at least 500mm clear for personnel access
to the delay lines or the metrology table.
The laser head is to be mounted at the south end of the table but provision should be made for
mounting a second laser at the N end of the table if room permits. At least 850mm between the end
of the table and the centreline of the nearest delay line is required to accommodate the laser head
and branch mirrors.
The metrology table should be positioned at least 600mm from the south wall of the BCA to allow personnel
access.
9.1.2 Metrology table height
The height of the table is determined by the height of the metrology beam expander assembly and the
incoming science beam height above the BCA floor. The nominal height of the centre of the incoming
science beam above the BCA floor is 1.6m. The base of the metrology system is 355mm below this and
therefore the nominal height of the top surface of the metrology table is 1265mm above the floor with an
allowance of +/-0.25mm for height setting and +/-0.1mm in the table surface error. Adjustment of the height
of the metrology table (with a sensitivity of approximately 0.1mm) must be provided as there is no height
adjustment in the individual metrology beam expander assemblies.
9.2
Electronics
Rack space in the outer BCA is required for a single 12U height VME crate is required for the metrology
measurement system. The parts required for the VME system are listed in RD4 but a portion of the table is
reproduced here in Table 1. In addition to the VME power supply at least 13 slots will be required depending
on the disc drive and any other peripheral devices/interfaces.
Rack space in the outer BCA is required to hold the power supply block for the laser head. The Agilent laser
has a power block rather than a rack-mountable module and a second block or 15V PSU will be needed when
more receivers are powered. Space is also require to hold up to 10 Agilent receiver modules which receive
signal from the remote sensors over optical fibre and convert it to voltages which are then connected to the
measurement board. A 3U height unit should be sufficient to house these modules and the power supplies.
Rack space of 15U for up to 10 1U height shear camera computer modules with a 0.5U minimum spacing
between each is required. They need not occupy the same rack as the VME system nor all be contained in
one rack.
The positioning of the rack(s) in the outer BCA used for housing the electronics should take into account the
available cable tray routes and the maximum cable lengths detailed in the following section. The preferred
location of all the electronics is in a single rack located in the outer BCA close to the south end of the
metrology table as shown in Figure 1 in the appendix.
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Table 1 Electronics in the rack positioned in the outer BCA
Component
Laser head power supply 2
Remote receiver 1
No.
1
110
Size4
-
Supplier
Agilent
Agilent
Part Number
10884B
E1709A
1
1
3
1
Concurrent
Technologies
Agilent
TEWS
Acromag
Acromag
Cambridge
Symmetricom
(13 slot min, with power supply
and fan cooling)
VP325/022-23U plus options as
required
10898A
TVME200-10
IP-220A-16
IP470A
Drawing set
TTM635VME-VCXO
-
Eurotech
VME system
VME card frame
1
16
VME CPU plus disc drive5
1
1+2
Measurement board 3
IP carrier board
8-channel D-A IP pack
Digital IO IP pack
Custom interface board
Timing and frequency
processor
Shear System
Shear camera computer1
1-5
1
1
1
1
1
APOLLO-ICE-G-P1.8FL-512MAC-NO_O/S
Unspecified
Unspecified
Unspecified
Keyboard
1
Monitor
1
KVM switch
1
Notes:1
One needed for every delay line.
2
Number depends on how many receivers are powered
3
One needed for every 2 delay lines.
4
Indicates module width for VME modules
5
VME cards are also available with on-board disc drives. Alternatively modules are available with disk,
DVD, floppy and other interfaces as required.
9.3
Cabling
Cabling between components on the metrology table and the electronics rack(s) is identified here in Table 2.
Table 2 Cabling between metrology system components.
Source
(Met Table)
Interferometer
remote sensor
Laser Head
Laser Head
Shear Camera
Destination
(Outer BCA)
Remote receiver
Function
No.
Cable Type
Measurement
signal
Measurement
signal
1-10
1-10
Agilent E1705E
opt 400
Agilent N1250A
1
Agilent 10881C 1
20m
1
Agilent 10881C 1
20m
1-10
Firewire
10m plus
4.5m repeater
as required
Remote receiver to
VME System
measurement board
VME System
Reference
measurement board signal
Power supply
and control
Shear Cam
Shear image
Computer
Notes: 1 This is a single cable combining power supply and reference signal (see appendix)
6
Maximum
cable length
20m
5m
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9.4
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Services
The following services are required for the metrology system:
•
Utility power for the VME rack
•
Utility power for up to ten shear camera computers each fitted with 180W power supply.
•
Utility power for the Laser head and receiver module power supplies 200W
•
One network socket at the metrology table. (Gigabit Ethernet recommended for displaying shear camera
images)
•
Ten network sockets for the shear camera computers. (Gigabit Ethernet recommended)
•
Ducting/cable trays for connections between metrology table and equipment rack(s)
9.5
Thermal loading
The laser will dissipate 35W while warming up but approximately 23W while in normal operation. A
significant proportion of this heat should be removed to meet the dissipation requirement of no more than a
total of 20W [TBC] apportioned to the metrology system within the inner BCA (RD1 & RD2). Each shear
camera will dissipate less than 1W and no explicit cooling will be necessary.
Air cooling for the laser head (RD5 and Figure 6) is required to be a minimum of 4m/s at the 50mm diameter
exit port, at ambient temperature, to remove 80% of the power dissipated in the head.
10 Design
10.1 Metrology Table
The optical layout of the metrology system provides for ten channels of metrology from a single laser which
is placed at one end of the metrology system. Provision for a second laser at the other end of the table should
be made in case one is required to maintain sensitivity of the measurement system. This requires a table area
which is long and narrow though the width could be increased to a standard size or more, if needed to
accommodate other BCA optics, but in any case no more than 1.8m. The layout of the laser metrology
system for the ten delay lines is described in RD4.
The distance between the inside of the south wall of the BCA and the centre of the first delay line
pipe is 5 feet 11 ¾ inches i.e. 1.82m (according to the architectural drawing given in RD6). The
preferred placement of the optical table along the N-S direction is such that there will be a 0.9m space
between the inner BCA wall and south end of the metrology table. This provides a distance of 920mm
between the edge of the table and the centre of the first delay line pipe (accommodating the 850mm
minimum requirement) and allows for cables from components on the table to be routed into the cable tray
directly above that end of the table. The diagram in Figure 1 in the appendix shows the laser mounted at the
S end of the table and the dimensions for positioning the table. The layout drawing for the metrology bench
within the BCF is available (AD3).
10.2 Connections
The connections between metrology components are listed in Table 2. Each cable is described in more detail
in this section.
10.2.1
Laser metrology
The laser head cable carries both the power supply to the head and the laser reference signal from the head.
The cable is 20m long and has a single connector at the laser but splits into to connectors at the other end.
See Figure 3 and Figure 4 for how the cable is connected. The remote sensor is not shown in Figure 3 but
connects to the remote receiver using a 20m glass optical fibre. The remote receiver is connected to the VME
measurement board using a 5m cable. Agilent require that the receiver modules are powered by +15V which
7
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is supplied via the measurement board to which they connect however the measurement board itself does not
provide this power, it is sourced externally and a suggested arrangement is outlined below.
A specially configured front panel ribbon cable is required to carry the reference signal from the first
measurement board to each of the other measurement boards in the system. It is not recommended to carry
the +15V supply to other measurement boards using this cable because the laser head power supply can only
supply two measurement modules at most when a 20m laser head cable is used. Therefore a different power
supply arrangement is required for supplying power to receivers via their measurement boards.
The measurement board does not supply the +15V however but all reference and signal input connectors (as
well as the front panel ribbon cable link which carries the reference signal to other measurement boards)
have this power connection bussed. Provided one of the two front panel reference signal connectors (dual
measurement board) is supplied with +15V then a receiver module plugged into either or both channels will
be powered. The first two receivers get power from the first measurement board via the reference signal
cable from the laser head. Further receivers are powered from their respective measurement boards provided
one of the other reference input sockets is supplied with power from the local +15V power supply in the
rack.
It is suggested that this additional +15V power supply provides power to each additional measurement board
via an individual cable which is plugged into one of the reference channel cables.
The power supply should be sized to provide 2.5A at +15V ±1V (for up to 8 receivers which each take
<270mA).
10.2.2
Shear Camera
No allocations are made but it should be noted that the shear camera fire-wire cable length is limited to 20m
for superior cable. If standard cable is used the limitation becomes 10m. Use of a repeater allows an
additional 4.5m of cable to the standard 10m length. The repeater draws power from the fire-wire cable and
therefore it would be undesirable to use more than one repeater per cable. Cable trays are approximately
2.5m above floor level and therefore cable length from the table surface to a tray directly above (if one is
available) is approximately 1.25m. The distance of the furthest shear camera from the south wall is
nominally 7.6m. Allowing the cable to rise and travel through the wall by the shortest route and then fall to
the same level implies a further 3m length making the total minimum length for this run 10.6m.
10.2.3
Mirror mount control
There is no cabled arrangement envisaged for controlling the motorised mirror mounts which are
incorporated into the metrology beam expander blocks. A handset may be plugged into the mirror mount to
be adjusted. If remote operation from outside the BCA is desired then further cabling and interfacing would
be necessary.
10.2.4
Grounding
In ‘Chapter 3 System Design Considerations’ of the Agilent Laser User Manual on laser measurement
systems, a subsection entitled ‘System Grounding’ describes the grounding practise that should be adopted.
This section is reproduced in Figure 8. The body of the laser will be connected to the metrology table while
the receiver modules will be mounted in the rack containing all the other metrology electronics. This
arrangement should be sufficient to comply with the grounding advice but if local regulations require that the
metrology table be grounded then an earth loop will be created which may affect the signal to noise in the
system. If explicit grounding of the metrology table is required then the best method would be to route that
ground with the laser head cable and connect it to an earthing point in the metrology rack. In this way the
loop area is minimised and it is unlikely that any other currents can flow through this earth link.
Alternatively the laser head mounting plate could be electrically isolated from the table using very thin
insulating film.
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10.3 Laser cooling
To prevent uncontrolled air exchange between inner and outer BCA an insulated enclosure will be placed
over the laser head and air introduced into it so that it can enter the cooling ports of the head. The exit port of
the laser will connect to the outside of this enclosure to ensure that air is forced through the laser head.
A conduit system to bring air from the outer BCA into the laser head enclosure and remove it again is to be
installed above each laser location at either end of the optical table. The interface details for this enclosure
are yet to be determined. [TBD]
11 Appendix
Figure 1: showing the minimum size and preferred position of metrology table.
Figure 2: showing the relationship of the metrology table surface to the incoming science beam
height and the nominal metrology table height above the inner BCA floor.
Figure 3: the Agilent single channel cabling arrangement
Figure 4: the Agilent 10881C laser head cable
Figure 5, 6 & 7: Specifications for the Agilent 5517FL and 5517GL laser heads.
Figure 8 System Grounding considerations
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N
INNER BCA
SOUTH WALL
ELECTRONICS RACK
(Preferred location)
0.6m
min
0.6m
min
7.2m min
BEAM EXPANDER
BLOCKS
METROLOGY BENCH
LASER HEAD
DELAY LINES
0.75m min
OUTER BCA
Figure 1Placement of metrology table in the inner BCA
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Figure 2 Position of the top surface of the metrology table with respect to the incoming science
beam height (355mm) and the nominal dimension for the metrology table height above the inner
BCA floor 1265mm (extracted fromAD3) .
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Figure 3 The Agilent cable arrangement for laser head, power supply, receiver and measurement
board. The remote sensor is not shown but connects to the receiver via an optical cable. The Agilent
power supply block and the receiver module(s) are to be located in the outer BCA.
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Metrology System to Beam Combining Facility ICD INT-406-VEN-0012 v0.4.doc
Figure 4 The Agilent 10881C Laser head cable.
13
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Figure 5 Specification sheet for the Agilent 5517FL laser head
Figure 6 Specification sheet for the Agilent 5517GL laser head. The laser dissipation is expected to
be the same as the 5517FL laser head.
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Figure 7 Specification sheet for the Agilent 5517GL laser head showing laser dimensions. Note that
a different mounting arrangement will be used so the three feet shown here will be removed (see
RD7).
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Metrology System to Beam Combining Facility ICD INT-406-VEN-0012 v0.4.doc
Figure 8 Extract from Agilent Laser System User Manual
16
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