BielefeldGED:Equipment

This page contains description of equipment used by GED group in Bielefeld.

News

Date	Record
13 May 2015	A valve for separation of the diffraction and mass-spectrometer chambers has been built.
22 May 2014	Hiden PIC 1000 series mass-spectrometer has been installed.
28 Feb 2014	A new booster pump (Edwards EH500) has been installed.
20 Dec 2013	A new diffusion pump (Edwards Diffstak 250/2000P) has been installed.

Instrument

The reconstructed Balzers Eldigraph KD-G2 (one of only two still existing ones worldwide) is presently in use in the laboratory. The most recent papers <bib id="BergerZFN2009" /> and <bib id="ReuterZNB2016" /> contain lots of details about this improved gas electron diffractometer.

Current state

• 

  The Hiden MS has been setup as residual gas analyser and a touch-control-panel has been established

History

• 

  GED instrument in April 2006 (Uni-Münster)

• 

  The apparatus with new gun, power supply and recording system (image plates), Jun 2007

• 

  November 2007, the apparatus is already in Uni-Bielefeld

• 

  September 2009, more control devices

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  May 2011, heavily improved control panel

• 

  The instrument in 2012

• 

  December 2013, new pumps installed

• 

  May 2014, the Hiden MS was installed for first measurements

Pumps

Backing Pumps

Backing (fore-vacuum) pumps: Edwards x05 Scrollpump Oilfree, Edwards E2M80 oil pump and Edwards EH500 booster pump. Our last oilfree pump worked 48822.8 hours. On the pictures is the new one.

Edwards E2M80 oil pump (left) and x05 Scrollpump Oilfree pump (right).

The same pumps from side.

More recent picture with the booster pump on top of the oil pump.

Diffusion Pumps

New diffusion pump (Edwards Diffstak 250/2000P), installed in December, 2013:

Old diffusion pump:

Turbo Pumps

Turbo pump (Edwards EXT70H) attached to the electron gun:

Sector

A sin²-type sector (15 cm in diameter, common formula is A*sin²(r/B)) is used.

Inlet Systems

Room-temperature Nozzle

Inlet device for room temperatures (used by Heinz Oberhammer).

Nozzle tip.

Medium-temperature Nozzle

This nozzle has been constructed for evaporation of compounds in a temperature range from 25 to 380 °C. However, it has also been successfully used for low temperatures below -15 °C.

General view of the inlet device.

A thin copper tube for a gas standard (like CO2) is shown.

A Swagelok valve is used.

Nozzle tip.

Cold Trap

Cold trap designed for using liquid nitrogen and installed from the opposite to the inlet system side.

In-line mass-spectrometer

A Hiden mass-spectrometer (PIC 1000 series, up to 2500 amu) with EPIC ion counting detector is attached to the electron diffraction unit.

General view of the EPIC detector.

Details of the tip.

In housing of the GED unit.

Valve for separation of the mass-detector and diffraction chamber.

Detection system

Imaging Plates (IP) are used for recording diffraction patterns. IPs are scanned with a Fuji BAS-1800II scanner and the signal is deleted using an eraser.

Fuji BAS-1800II scanner.

Eraser from Raytest company.

BAS-MP 2025 IPs.

References

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