PROJECT PROGRESS

2nd. Quarter 2021
The first tests of the improved cathode prototype have shown very promising results. The
performances of a 20 W cathode power are displayed in the figures.

Prototypes at ATD for delivery to UPM, JLU Giessen, and FOTEC.

The UPM team has set up
the vacuum equipment
and data acquisition
system for low pressure
discharge plasma cathode
endurance testing.

Several characterization tests have been performed on 8 different C12A7:e- production batches, each one with a different electron concentration, with 5
characterization techniques: Electron Spin Resonance, Raman, Hall Effect, Thermionic emission, and Kelvin Probe Force Microscopy.

Figure shows the operation of a cold plasma source rst tests performed
at UPM on the cold plasma source designed by the UPM for the
thermionic electron emission tests of NACES cathode.

1st. Quarter 2021

First prototype tests at ATD have shown an outstanding performance
of the C12A7:e- material when operating under ionized gases. Cathode
design improvements are being introduced and new prototype versions.

Testing the same cathode design to compare LaB6 material under Xe and Ar gas flows, showed a higher performance of C12A7:e- material.

JLU performed comparison tests of some C12A7:e- samples from
ATD that have been used at EXOTRAIL and at JLU, obtaining
comparable results in terms of Work Function.

The data acquisition and control software for UPM test activities has been checked and validated in a realistic electron emission experiment using a DC heated tungsten hairpin.

First tests performed with the EXOTRAIL 1A lab prototype comparing LaB6 and C12A7:e- materials.

4th. Quarter 2020

Preparation at JLU of the samples and the test environment for the first Hall measurements on conductivity.
Successful manufacturing at JLU workshop of a test hollow insert from a C12A7:e- cylinder, reducing external diameter and drilling the central hole.

Thermal camera measurements performed by Exotrail revealed thermal gradients of up to 50 ºC across the emitting surface of C12A7:e- .

Exotrail laboratory C12A7 cathode is now ready and tests have started for LaB6 and awaiting for C12A7:e- samples.

Finished the build up of the test chamber Dory at JLU Giessen, which is now fully operational for neutralizer testing, starting by the Hollow Cathode with LaB6 insert.

Heater containers have been finally manufactured at ATD based on the different tests performed on heater radiation confinement techniques and
materials.

Conductivity increase with
temperature verified in ATD lab tests.

September 2020
Completion of the vacuum chamber, test environment, and control and data adquisition SW at UPM.

Exotrail did perform 5 A cathode operation test both with LaB6 and with C12A7:e– for perfomance comparison purposes. Self-heating operation of C12A7:e– electride was got at 0,2 – 2,2 A.

FOTEC has documented the first thermionic emission got from a C12A7:e– thin film deposition via sputtering technique.

August 2020
Thermionic emission comparison tests performed at Exotrail for LaB6 and C12A7:e– emitting surfaces of 6 mm diameter disc.

Set-up improvements developped by Fotec.

Successful ignition and operation of neutralizer with LaB6, and thermal models of electride and LaB6 developed at JLU.

July 2020
New samples batches of C12A7:e- with high electron density produced at ATD