Modular design

The digital display of the power supply can be used independently or other experiments, such as photoelectric effect, nuclear magnetic resonance, etc.

The wide voltage power supply design can be switched between 110V and 220V, which is suitable for use in most countries.

The Helmholtz coil module contains a pair of coils and an excitation power supply, which can change the size of the magnetic field and has strong versatility. It can be used for experiments such as Helmholtz coils and is more widely used.

Optional PASCO Capstone software for image acquisition and analysis of electron beam

PASCO Capstone software can be used to record the whole process of electron beam deflection under the action of magnetic field, measure the radius of the electron beam forming a closed circle, and calculate e / m or other parameters through the formula editor.

Rotatable Thomson tube

The Thomson tube with vertical design can better observe the trajectory of the electron beam
The Thomson tube can be rotated from -45 ° to + 45 °. Students can rotate the Thomson tube to observe the deflection trajectory of the electron beam when it is subjected to Lorentz force in different directions in the magnetic field.

Fluorescence scale

Fluorescence scale can observe the position and radius of electron beam even in dark environment.

Observation box for physics experiment observation

A shading dark box can be selected for the charge-to-mass ratio base, so that the experiment is no longer affected by ambient light.

Typical experiment and data

1. Observe the trajectory of the electron beam in the magnetic field

In the absence of an external magnetic field, the electron beam trajectory

In the case where the applied magnetic field is perpendicular to the exit direction of the electron beam, the trajectory of the electron beam is a closed circle.

In the case where the applied magnetic field is not perpendicular to the exit direction of the electron beam, the trajectory of the electron beam is a spiral.

2. Calculate the electron Charge-to-Mass ratio

R = 158mm N = 130 turns

B=(4/5)3/2 × μ0• N • IH / R
e/m=2U• (5/4)3• R2 / (N • μ0 • IH • r) 2 ；
The relative error between e / m measured value and theoretical value is less than 5%.

Parts list

BEM-5002    Adjustable DC (constant voltage) power supply II, 12V / 100V / 200V