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5H60.10 - Einstein De Haas Effect

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5H60.10 - Einstein De Haas Effect

Title5H60.10 - Einstein De Haas Effect

Demonstrate the spin angular momentum of electrons.

Assembly Instructions

​Use the dedicated Einstein de-Haas setup (only use Coulomb law setup as alternative).   

**Be sure to remove the foam inserts when running the appartus, but be sure to replace the foam inserts whenever the cart is in motion.** 

Connect the solenoid to the output of the Samson SX2400 amplifier.  Make sure the amplify is on a single channel (not bridged).  Connect the arbitrary function generator to the input of the amplifier and set the frequency to the resonant frequency of the torsion suspension (~1.8 Hz).  Turn the amplifier output to about 10 'o-clock on the knob.  Allow to run for about a minute for the resonant effect to become visible. 

**Be sure to inform instructors not to turn up the amplitude above the 10 o-clock setting or it will overheat the solenoid**

Setup Time5
Operation Time5
Preview Time5
Operation Instructions

Set the frequency generator to 1.8 Hz.  Turn up the amplifier to the 10 o-clock point on the knob.  Wait about a minute for the system to become resonant.​

**Do not turn up the amplitude above the 10 o-clock setting or it will overheat the solenoid**
Demo on DimeNo
PIRA 200No
Export Instructions (if different)
HazardsFragile: Caution when Transporting

Discovered in 1915, the Einstein-De Hass effect is a relationship between magnetism, angular momentum, and the spin of electrons. The experimental setup consists of a ferromagnetic body that is suspended inside a solenoid by very thin wires. A mechanical rotation of the ferromagnetic body can be achieved slowly over time when an AC current is applied through the solenoid at a resonant frequency. The mechanical rotation results from the conservation of angular momentum. When the electrons magnetic moments align with the applied field, their angular momentum changes producing a torque on the ferromagnetic body. This is a beautiful experiment describing a connection between classical and quantum physics.

Category5 Electricity and Magnetism
Subcategory5H - Magnetic Fields and Forces
KeywordsElectron Spin, Angular Momentum, Spin Angular Momentum, De Haas, Einstein
Construction Information
amplifier - Samson SX2400
cable BNC to RCA
cable RCA to 1/4"
banana cable
coulombs law apparatus - suspension
solenoid - cenco
bench clamp
rod - short
rod clamp
clamp 3-fingered
camera - b&w
blocking plate
Function Generator - GW Instek
Rod - Steel, De Haas Effect
Coulomb setup- Steel Suspension Wires
Sign - demo specific setting