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A beam of positive ions traverses for a distance l=4cm an electric field |E|=500

ID: 1689551 • Letter: A

Question


A beam of positive ions traverses for a distance l=4cm an electric field |E|=5000 V/m and a parallel magnetic field |B|=0.01 tesla. The ions travel perpendicular to the direction of the two fields (parabola method). They then cross a field-free region l'=18cm and land on a flat fluorescent screen. What are the parameters of the parabolas on the screen if the beam consists essentially of singly charged hydrogen ions and hydrogen molecules with a velocity corresponding to an accelerating voltage between 1000 V and 4000 V? What does the image on the screen look like if both positively and negatively charged ions are directed at it?

Explanation / Answer

A beam of positive ions traverses for a distance l=4cm an electric field |E|=5000 V/m and a parallel magnetic field |B|=0.01 tesla. The ions travel perpendicular to the direction of the two fields (parabola method). They then cross a field-free region l'=18cm and land on a flat fluorescent screen. What are the parameters of the parabolas on the screen if the beam consists essentially of singly charged hydrogen ions and hydrogen molecules with a velocity corresponding to an accelerating voltage between 1000 V and 4000 V? What does the image on the screen look like if both positively and negatively charged ions are directed at it?