Vacuum Pump System
- Kodi Rider
- Steve Gibson
Table of Contents:
Introduction
Given the high stability requirements of KPF, the main spectrometer sits within a vacuum chamber in order to isolate the spectrometer from its environment. This provides isolation against changes in atmospheric pressure and also convective thermal disturbances.
The vacuum pump system for the KPF vacuum chamber consists of a turbo pump backed by a roots pump. The Leybold TurboVac pump is controlled via a Leybold Turbo.Control controller, which contains a webserver to allow control of the pump via a webpage in a browser. The Leybold EcoDry roots pump is simply turned on and off via a PDU outlet on the Vac Cart.
Within KPF the turbo and roots pump run continuously.
The Turbo.Control controller also allows connection of two vacuum gauges; we use both of these ports to connect a low and a high vacuum gauge. These two gauges monitor the vacuum pressure within the pipe going to the main KPF vacuum chamber. They are mounted on the Vac Cart and sit on the Vac Cart side of the main chamber gate valve.
Direct computer control of the TurboVac pump is possible via serial commands, however creating a full KTL dispatcher for the pump was deemed too difficult given the dozens of commands required, as well as the fail-safes required to not damage the pump. As such we decided to use the vendor-supplied web-based software to control the pump, which has all the features we need built-in. Since this webpage also provides pump telemetry, we wrote a KPF KTL dispatcher to monitor this webpage and write telemetry values to KTL keywords.
Relevant Devices
Description | Qty | Source | Part Number | Notes |
|---|---|---|---|---|
Turbo Pump | 1 | Leybold | LH TurboVac 450iX |
|
Turbo Pump Controller | 1 | Leybold | Turbo.Control i |
|
Roots Pump | 1 | Leybold | LH EcoDry65 | No computer control |
High Vac gauge | 1 | Leybold | PTR 90 N | Combo Pirani and Cold Cathode gauge |
Low Vac gauge | 1 | Leybold | TTR 91 N S | Pirani gauge |
Relevant Functional Block Diagram
Cable Details
Cable | Qty | Details | Notes |
|---|---|---|---|
Ethernet | 1 | Cat6 Copper Ethernet Cable M-M, 6 feet long | Entirely within Vac Cart. |
Gauge Cable | 2 | Shielded RJ-45 | Shipped with Gauges |
RS-485 | 1 | DB-9 M-M, 3 feet long | Shipped with TurboControl or TurboPump |
Photos of Devices
Relevant Datasheets & Manuals
Description | File | Source | |
|---|---|---|---|
| 1 | EcoDry Roots Pump Manual |  |
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| 2 | Turbo Pump Operating Manual | 
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| 3 | Turbo.control Gauge and Pump Controller |  |
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| 4 | Serial Interfaces for TURBOVAC |  |
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| 5 | Pump Power Supply “Brief Instructions” |  |
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| 6 | ‘Vacuum Measurement’ brochure containing specs on various gauges, including both of our gauges (PTR 90 N and TTR 91 N S) | 
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| 7 | PTR 90 N Vacuum Gauge ‘Technical Data’ sheet | 
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| 8 | CAD Model for PTR 90 N gauge. | 
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| 9 | Datasheet for TTR 91 N S gauge. Seems a bit outdated, and was downloaded from a vac supply company (not Leybold). However there was nothing on this part number at Leybold (closest was a TTR RNS model, which might be the newer version of our gauge). | 
| http://vacshop.ir/wp-content/uploads/2016/02/vacshop-THERMOVAC_New-TTR91N.pdf |