Cathode ray tube magnetic deflection by horseshoe magnet

A weak magnet is used to deviate the cathode rays generated by a  Cathode-ray Tube. The north pole is moved close to the tube along the horizontal plane and the rays go down, then the south pole is moved  close to the tube along the horizontal plane and the rays go up.

Then a more powerful horseshoe magnet is used. The north pole is red, the south pole is green. The magnetic force lines can be thought exiting from the north pole and entering the south pole of the magnet.

The tube was operating at about 3.5 kV

Cathode-ray Tube is mod. DE453-3S Kathodenstrahlröhre mit Spalt from Fruhmann GmbH
https://shop.ntl-shop.at/global/

Horseshoe Magnet is mod. EDU-5 100 x 63 mm made of AlNiCo5 from supermagnete
https://www.supermagnete.it/