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

Nikhil Gaikwad; Lichao Liu; Matthew Peter Griffiths; Mathias Østbjerg Vang; Denys Grombacher; Jakob Juul Larsen

Abstract

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 remote
field measurements.

Original language	English
Publication date	Oct 2022
Number of pages	3
Publication status	Published - Oct 2022
Event	The 8th International Workshop on Magnetic Resonance Sounding - University of Strasbourg, Strasbourg, France Duration: 26 Oct 2021 → 27 Oct 2021 Conference number: 8 https://mrs2021.sciencesconf.org/

Workshop

Workshop	The 8th International Workshop on Magnetic Resonance Sounding
Number	8
Location	University of Strasbourg
Country/Territory	France
City	Strasbourg
Period	26/10/2021 → 27/10/2021
Internet address	https://mrs2021.sciencesconf.org/

Keywords

instrumentation
SYSTEM
Thermal Stability
Mathematical modeling

Access to Document

https://mrs2021.sciencesconf.org/data/pages/proceedings_MRS2021_distrib_v2.pdf

Cite this

@conference{2ad59b79883c4927a304e0937ea16a0d,

title = "Thermal Model of the Apsu Transmitter for Lightweight and Compact Heat Sink Design",

abstract = "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.",

keywords = "instrumentation, SYSTEM, Thermal Stability, Mathematical modeling",

author = "Nikhil Gaikwad and Lichao Liu and Griffiths, {Matthew Peter} and Vang, {Mathias {\O}stbjerg} and Denys Grombacher and Larsen, {Jakob Juul}",

year = "2022",

month = oct,

language = "English",

pages = "11--13",

note = "The 8th International Workshop on Magnetic Resonance Sounding, MRS2021 ; Conference date: 26-10-2021 Through 27-10-2021",

url = "https://mrs2021.sciencesconf.org/",

}

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 -