1. MAGNETIC FIELD MEASUREMENTS ELECTROMAGNET POWER SUPPLY
Quantum Electronics Laboratory
Faculty of Physics
Adam Mickiewicz University in Poznań
MAGNETIC FIELD MEASUREMENTS
AND
ELECTROMAGNET POWER SUPPLY
Stanisław Niziński
Goal: create project of autonomic system, controlling electromagnet and measuring magnetic field.

2. MAGNETIC FIELD SENSORS*
MAGNETOMETERS
B < 1 mT
GAUSSMETERS
B > 1 mT
 Fluxgate
 Induction Coil
SQUID
Magnetoresistive …
 Hall Effect
 Magnetoresistive
 Magnetodiode
Magnetotransistor …
Hall effect sensor is the most common sensor used to measure high magnetic fields.
*Macintyre, Steven A. "Magnetic field measurement."  ENG Net Base (2000). CRC Press LLC. Retrieved 29 March 2014.

3. Measuring magnetic field
Special semicondiuctor Hall Sensors were applied, they have almost constant parameters in 2K - 300K temperature range.
There are 5 Hall Sensors located at the measurement unit. It can measure magnetic field in X, Y, Z axes. To measure gradient, we need 2 sensors in one axis, so magnetic field gradient can be measured in X and Y axes only.

4. Measuring magnetic field
external Hall sensor (H0)
There is Hall sensor outside the electromagnet, calibrated to determine magnetic field inside the electromagnet during it’s work.

5. Power supply controller

6. Power supply controller software
interruption
every ≈100ms
measure magnetic field
is field in range?
finish
procedure
YES NO
1. switch on heater
2. switch on power supply
measure magnetic field
increase current
Is field big enough? NO
YES
1. switch off heater
2. switch off power supply
finish
procedure

7. Measurement setup

8. Schematic of LabView measuring program

9. THANKS FOR YOUR ATTENTION
THAT’S ALL
THANKS FOR YOUR ATTENTION