Automated High Vacuum Chamber Rich Barry Alex Wallace Ian Joseph - - PowerPoint PPT Presentation

Automated High Vacuum Chamber

Advisor:

• Dr. Jim Tan-atichat

Sponsor:

CSU, Chico Physics Dept.

• Dr. Eric Ayars

Ian Coltrin Rich Barry Alex Wallace Joseph Vranich

Background and Need

Need Statement: The CSU, Chico Physics Department needs a vacuum chamber to perform a greater variety of experiments for students and faculty alike. Goal Statement: Design, build, and test a vacuum chamber that achieves high vacuum made with parts already donated.

Project Requirements

The Design Solution Must:

• Be capable of producing and maintaining high

vacuum

• Be capable of automated operation

The Design Solution Should:

• Be modifiable/modular
• Have hardware support for future lab work
• Be usable by students
• Have a control system programmed in a familiar

environment

It Would Be Nice if the Design Solution:

• Was mobile
• Included a closed loop cooling system

Metrics/Targets

Requirement Engineering Specification Metric Method/Device Target Condition High Vacuum Pressure Torr High Vacuum Pressure Gage 10-6 -10-7 Torr Maintained for at least 3 hrs.

Design Changes

• Mechanical
• Custom Chamber Support
• Custom 'double-port'
• Foreline and venting components

Diameter reduction

• Additional donation integration
• Mechatronic
• Control system sensors
• Control interface
• Pump-down procedure

Design Solution

interface screenshot

Double Port

• Needed flexibility in future chamber arrangements
• Each face of the main chamber is valuable
• Choices for the connection of the foreline and the IG
• Individual 6-way faces for IG and foreline

Wasteful

• Combine foreline and IG connection into one face

Potential for bad gauge reading? Non-issue

• Custom component allows for multiple positions

Foreline Design

• Metal bellows tubing used to prevent collapse under vacuum
• Additional donated inline valve altered the foreline
• Redesigned the venting system to use a solenoid

Chamber Body and Sealing

All chamber components cleaned with Acetone and Isopropyl

• Alcohol. All seals given a small coat of vacuum grease

Once under vacuum, all gaskets compress and seal tightly

Possible Double Port Attachments Actual Configuration

Control Software

• State machine in LabVIEW
• Monitors system state for safe operation
• Fully auto and "manualmatic" modes
• Interfaces to the real world using USB DAQ
• Fine tuning of the pump down procedure accomplished

during test runs

• Allowed "Software in the Loop" & "Hardware in the Loop"

development

"Software in the Loop" Vacuum Control 1.0 Basic control state machine Vacuum Control 2.0 Correct pumping sequence User interfacing "Hardware in the Loop" Vacuum Control 3.0 & 3.1 Sensor interfacing I/O Restructuring Vacuum Control 4.0 Statistical smoothing of sensory data Error handling

VI Generations

Instrumentation and Interfacing

• Main Chamber Pressure
• Combination ion gauge reads from atmosphere to high

vacuum RS-485 Interfaced via NI RS-485 to USB cable

• Foreline Pressure
• Thermocouple gauge

Interfaced using BoB A/D Measures ATM to rough vacuum

• Coolant Temp
• Thermistors installed in coolant lines

Wheatstone bridge Measured by BoB A/D

RS-485 Interface, Thermistor Circuits

Power

115VAC / 58 Amps

• Total potential power draw for the system
• No power source previously in the lab could support this
• Installed additional power source
• 2-pole 115VAC 30A
• Distribute the power to various loads in the system
• Control the power to the loads, control the loads

PDU Wiring Schematic

Pneumatics

• Powered by 100 psi on board air compressor
• Dual Manifolds with Regulator
• Split Pressure Ranges
• Pneumatic tubing with one touch fittings allows for ease of

use and greater modularity

Cooling

Open loop cooling with temperature monitoring using 2 wire resistance thermistors. 1) 2) 3) 4)

Fabrication/Assembly

Mark 1

• So excited to get parts, built a test stack to check the rough

pump

• Built the pump stack to test seals and connections
• Performed pump maintenance on both pumps to improve

performance

• flushed oil reservoir
• cleaned filters
• oil change

Mark II

• Received more parts
• Built chamber body using 6-way
• Installed ion gauge
• High vacuum ready
• Pumped down to high vacuum and began fine tuning the

system software

PDU Fabrication

• Installed SSR's for power control
• Manufactured copper bus terminals for power distro
• Prototyped a driver board for SSR/solenoid control and BoB

interfacing

• Mounted wall sockets on the front of the case, simple plug

and play operation

• Appropriate circuit protection installed
• Circuit breakers for each major load

PDU Fabrication Process

Mark III - The Final Mark

Testing

Reaching the End Goal

Test Data

Checks: Autonomous valve operation Final Pressure Time to High Vacuum Correct user prompting

Checks in the Boxes

Requirements: Should Modifiable/Modular Support equipment for future experiments Usable by students Programmed in a familiar language Would be Nice Mobile Closed loop cooling

Final Budget

Component Price Overall Chamber $866 Foreline (Tubing, Feedthrough) $2234 Valves/Pneumatics $132 Misc (Cold Cap) $450 Total $3682

Final Budget Summary:

Component Price High vacuum gauge $972 PC $300 Breakout Device $99 Power Supplies $22 Misc (wire, terminals, etc.) $250 Total $1634

Mechanical Mechatronic

Component Price Chamber Pieces $14096 Foreline Connections $283.50 Valves $4029 Total $18408.50

Donated Total Purchased: $5316.00 Total Cost Overall: $23724.50

Labor

Design Mechanical Electrical Software Total Hours 416 441 260 1153 Cost $14,547.50 $15,421.80 $9,092.20 $40,320.40 Assembly and Test Mechanical Electrical Control System Total Hours 650 450 700 1352 Cost $22,730.47 $15,736.43 $24,479.00 $62,945.9

Fall 2009 Spring 2009

Why this system is so cool

• Automated vacuum systems are normally expensive
• Design provides a great learning environment
• Built on a lean budget
• Achieved high vacuum (900 nTorr) within 45 minutes on the

first attempt!

Suggested Future Changes

• Addition of a thermal evaporation system and other

experiments

• Makes the chamber useful
• Closed loop cooling system
• Simple and inexpensive designs available
• Creates a more conservative and cost effective system
• Oil Vapor Filter for the Roughing Pump
• Conserves oil
• Keeps the system clean inside and out

Acknowledgements

Craig Myers, Gino Giordano, Doug Reid from Duniway, Paul Young from Adixen, Jordan Lynn from NI, Dr. Ayars, Robert Kieth, Nick from FMS, Lisa Washburn, Dr. Gaffney, Dr. Ayars, Collier's Hardware staff, Mike Kellog From LAM who donated parts, Dale Word, etc...

Thanks Everybody!

Questions?