Thermal Model of the Apsu Transmitter for Lightweight and Compact Heat Sink Design

TY - ABST

T1 - Thermal Model of the Apsu Transmitter for Lightweight and Compact Heat Sink Design

AU - Gaikwad, Nikhil

AU - Liu, Lichao

AU - Griffiths, Matthew Peter

AU - Vang, Mathias Østbjerg

AU - Grombacher, Denys

AU - Larsen, Jakob Juul

N1 - Conference code: 8

PY - 2022/10

Y1 - 2022/10

N2 - The compact and flexible Apsu instrument has been developed to deliver 105 A and up to 150 kW of instantaneous power during the transmission. The Apsu transmitter unit (ApsuTx) control and regulate this high current where some amount of transmission power is dissipated as thermal energy. Therefore, thermal management of this unused power becomes an impotent concern for reliable operation of the ApsuTx, especially for new steady-state sequences. We briefly introduce the ApsuTx circuit and provide a mathematical formulation for electrical power dissipation. This formulation is used to design the thermal model of ApsuTx and it is evaluated using different input sequences. The comparison results showed that 33.93 W is dissipated by steady-state sequences, which is approximately ten times more than with conventional pulses. This power can only be dissipated safely by a heatsink with a maximum thermal resistance of 1.832 oC/W. A small size heat sink (300 mm × 200 mm × 8 mm) has been designed and installed with a lower thermal resistance than the calculated value. This provides a compact and lightweight solution for remotefield measurements.

AB - The compact and flexible Apsu instrument has been developed to deliver 105 A and up to 150 kW of instantaneous power during the transmission. The Apsu transmitter unit (ApsuTx) control and regulate this high current where some amount of transmission power is dissipated as thermal energy. Therefore, thermal management of this unused power becomes an impotent concern for reliable operation of the ApsuTx, especially for new steady-state sequences. We briefly introduce the ApsuTx circuit and provide a mathematical formulation for electrical power dissipation. This formulation is used to design the thermal model of ApsuTx and it is evaluated using different input sequences. The comparison results showed that 33.93 W is dissipated by steady-state sequences, which is approximately ten times more than with conventional pulses. This power can only be dissipated safely by a heatsink with a maximum thermal resistance of 1.832 oC/W. A small size heat sink (300 mm × 200 mm × 8 mm) has been designed and installed with a lower thermal resistance than the calculated value. This provides a compact and lightweight solution for remotefield measurements.

KW - instrumentation

KW - SYSTEM

KW - Thermal Stability

KW - Mathematical modeling

M3 - Conference abstract for conference

SP - 11

EP - 13

T2 - The 8th International Workshop on Magnetic Resonance Sounding

Y2 - 26 October 2021 through 27 October 2021

ER -