For a better understanding of how an electron time-of-flight analyzer is built, I took pictures during the assembly of TOF 5.

All the parts needed for the analyzer.

The electrostatic lens system

entrance aperture

lens elements

assembled lens system

CoNetic and Retarding Tubes

CoNetic Tube with lid and ring to hold the lens system (see above) are on the left and retarding tube with insulation ring that goes between the two tubes, are on the right.

Back end of CoNetic Tube with holes for pumping the inner analyzer region and front end of retarding tube

View into the retarding tube from the back end

Extension tube with teflon pivot ring and mounting ring for 8" flange of T-Flange

Retarding tube sits inside a teflon ring that supports the front end of the analyzer. The retarding tube can pivot inside the telfon ring for alignment purposes (left). Retarding tube with mounted mesh through which the turbo pump provides a good vacuum at the back end of the analyzer (right).

The back end of the CoNetic Tube is mounted in the analyzer alignment system.

The back end of the retarding tube is mounted inside the CoNetic Tube.

Analyzer Alignment System

Two rings are employed to align the analyzer. The inner ring sits on two rods that are mounted in an outer ring. A rotary motion feedthrough (left) pushes and pulls the ring back and forth inside the outer ring. The outer ring is attached to a linear motion feedthrough (right) that pulls and pushes the outer ring back and forth. Both feedthroughs are mounted perpendicular to each other.

The front end of the linear motion feedthrough shown with part of the outer ring where it attaches to.

Adaptor to link the inner ring with the rotary motion feedthrough

The two rings have to be mounted inside the Pump and Feedthrough T-Flange to the linear motion feedthrough.

Pump and Feedthrough T-Flange

The T-Flange has six ports. Two 8", one for the MSP mounting and one for the chamber, one 4.5" for a small turbo pump, two 2.75" for the two motion feedthroughs and one 2.75" for two electrical feedthroughs that sit on a flange (see right picture, left hand side).

Coupling for rotary motion feedthrough to inner ring.

T-Flange with one (right) and both motion feedthroughs mounted (left)

T-Flange with alignment rings and CoNetic Tube inside (right) and T-Flange with extension tube mounted (left)

The analyzer is assembled and ready to get mounted onto the vacuum chamber.

BackView from the side of the MCP mounting

Side Views

FrontView towards the entrance aperture

Micro-Channel-Plate (MCP) / Micro-Sphere-Plate (MSP) Mounting

Two MCPs or one MSP with a diameter of 2" are the heart of the electron detector. The MSP and MCPs are not shown in this photo. The 8" flange has high-voltage electrical feedthroughs and a honeycomb mesh that sits right above the MCPs. The anode (not shown either) sits in the hole underneath the plates.

Other ways to use the analyzer (not recommended)

Wayne the DDS "open wider"

Send comments to Oliver Hemmers.

Last updated on May-31-2000.