UPDATE LOG

  • 03/14/2018 – Build details and technical specifications page officially released. Roughing system tested and qualified, with thermocouple gauge calibrated, and the blanked off system exceeding its goal of 15 microns by achieving an ultimate vacuum of 12 microns.
  • 03/16/2018 – Technical drawing sheets officially released. High vacuum design calculations for the V4 system and prior system iterations officially released.
  • 05/09/2018 – Assembly started on the high vacuum chamber.
  • 07/01/2018 – New system goals and direction of project identified – the V4 system will now be used for the testing and development of miniaturized low-voltage intense plasma-cathode electron guns and explosive electron emission velvet-cathode based electron guns.
  • 08/01/2018 – Project officially put on hold until further notice due to lack of personal funds for completion and the development of several larger scale higher power systems. Progress will resume once the cooling system, control system, and new high vacuum pumping systems are developed and tested.
  • 08/21/2018 – During preliminary testing and qualification of the closed-loop diffusion pump cooling system, it was discovered that the water-cooled baffle is made from steel instead of stainless steel, causing severe rusting. As a result, this component will no longer be used for the V4 system. A new system topology is under development with a larger stainless steel 8″ baffle for use with the micro propulsion testing chamber that will be implemented for use with the V4 chamber as well.
  • 08/21/2018 – AS OF NOW, THE V4 DESIGN IS OFFICIALLY OBSOLETE. NEW DETAILS OF THE FINAL V5 DESIGN CAN BE FOUND ON THE SMALL SCALE MULTIPURPOSE HIGH VACUUM SYSTEM V5 PROJECT PAGE.

 

OVERVIEW

The Small Scale Multipurpose High Vacuum System is a compact and low-cost multi-functional platform used for the testing and developing of small scale charged particle beam and plasma systems. The system will feature a modular form factor based off of 2.75″ conflat hardware in an efficient and expandable topology. The current system design V4 is rated for operation between 10^-2 Torr to 10^-7 Torr. The vacuum system is pumped by an Edwards EO4 diffusion pump with a chilled baffle to eliminate backstreaming into the chamber. Isolation and system conductance is controlled via an inline 2.75″ CF manual gate valve. The chamber itself consists of a 5-way 2.75″ CF cross with a dedicated front optical viewport and 3 input ports for a variety of testing apparatus. Instrumentation includes a Pfeiffer HPT-100 Wide Range Vacuum Transducer on the high vacuum side, and a calibrated VGT-1504 thermocouple gauge on the roughing line.

 

TECHNICAL DOCUMENTATION

  1. PRELIMINARY DESIGNS AND CALCULATIONS (V1-V3)
  2. CURRENT DESIGN CALCULATIONS (SYSTEM V4)
  3. TECHNICAL DRAWING SHEETS ARCHIVE
  4. THERMAL ANALYSIS OF THE EDWARDS EO4 DIFFUSION PUMP
  5. THERMAL ANALYSIS OF AN OPTICALLY DENSE WATER COOLED BAFFLE ASSEMBLY
  6. BUILD PICTURES
  7. PUMPDOWN AND CALIBRATION DATA

 

TECHNICAL SPECIFICATIONS

ROUGHING SPECIFICATIONS

  • Roughing Pump – Yellow Jacket SuperEvac 93560
  • Low Vacuum Sensor – VGT-1504 Thermocouple Gauge (S/N 5078)
  • Foreline Trap – FL20K Foreline Trap w/ Zeolite Pellets
  • Foreline IsolationNorcal 90 Degree Manual KF25 Valve
  • Ultimate Tested Foreline Pressure (Isolated) – 2 x 10^-3 Torr (2 microns)
  • Ultimate Backing Pressure (Isolated) – 1.25 x 10^-2 Torr (12.5 microns)

HIGH VACUUM SPECIFICATIONS

  • Main High Vacuum Pump – Edwards EO4 Diffusion Pump
  • Diffusion Pump Oil – DC 705 Equivalent
  • Baffle – Optically Dense Chilled Baffle
  • High Vacuum Sensor – Pfeiffer HPT-100 Wide Range Vacuum Transducer
  • High Vacuum Pipeline – 4 Way 2.75″ CF Cross
  • High Vacuum Isolation Valve – 2.75″ Manual Gate Valve
  • High Vacuum Chamber – 5 Way 2.75″ CF Cross

AUXILIARY SYSTEM SPECIFICATIONS

  • Control and Monitoring – Raspberry Pi with Distributed Arduino Modules
  • Sensor Inputs – Coolant temperature, coolant flow, low vacuum pressure, high vacuum pressure, power supply feedback
  • Primary Cooling – Multi-loop PID controlled chilled propylene-glycol to water cooling system
  • Baffle Cooling – Multi-loop PID controlled chilled propylene-glycol cooling system
  • Power – 120VAC, 5VDC, 12VDC, 24VDC

PLANNED EXPERIMENTS

  • High Pressure 25kV Multi-Megawatt Pulsed Glow-Discharge Cathode Electron Gun
  • Miniature Multi-Megawatt Nanosecond Pulsed EEE Electron Beams
  • Intense Pulsed Ion Source
  • Project Type: Multipurpose High Vacuum System
  • Operational Vacuum Levels: 10^-2 Torr to 10^-7 Torr
  • Planned Experiments: Electron Guns, Ion Beam Sources, Plasma Sources
  • Status: Obsolete