FOCAL e

FOCAL e- (acronym of Facility for Calibration At Liège in Irradiation) is a vacuum chamber on a horizontal configuration with 0.8 m diameter and 0.8 m long.

Characteristics

Sources

The cover at the front face contains 4 electron transparent light blind windows.

Four β^- radioisotopes as electrons sources can be used. All sources were placed on a source wheel. The sources can be for example:

• 3.7 kBq of ¹⁴⁷Pm (half-life: 2.6234 years),
• 37 kBq of ³⁶Cl (half-life: 3.02E5 years),
• 3.7 kBq of ⁸⁹Sr/⁹⁰Y (half-life: 28.5 years),
• 37 kBq of ¹⁰⁶Ru (half-life: 1.02 years),

The facility provides electrons in the 0 - 3.5 MeV range with fluxes at device under test location up to 6000 e-/s.cm².

Detector

The Focal e^- facility includes a reference electron spectrometer. The device is a ESLB 200-5000 Si(Li) spectrometer from Canberra. This spectrometer has a resolution of 1.7 keV (@ 624 keV) and is cold thanks to a LN2 bath.

Residual Gas Analyser

A mass spectrometer is installed on the chamber in order to analyze the residual gas (AMU 1-200).

Electrical flange

On one side of the chamber, there are flanges for electrical feedthroughs.

Pumping system

The pumping cycle is divided into 2 steps:

• primary pumping
• turbomolecular pumping

This pumping system is designed to reach 5 10^-3 Pa after 2 hours of pumping.

Crane

A 1.5T crane is used to install the set-up and specimen in the chamber.

Data Handling

The data acquisition of Focal e^- is realized by Keithleys 2701 data loggers with industrial PC’s.