Editing Solenoid (section)

=== Irregular solenoids ===
[[File:Irregular solenoids.jpg|thumb|Examples of irregular solenoids (a) sparse solenoid, (b) varied-pitch solenoid, (c) non-cylindrical solenoid]]

Within the category of finite solenoids, there are those that are sparsely wound with a single pitch, those that are sparsely wound with varying pitches (varied-pitch solenoid), and those with varying radii for different loops (non-cylindrical solenoids). They are called ''irregular solenoids''. They have found applications in different areas, such as sparsely wound solenoids for [[wireless power transfer]],<ref>{{cite journal |first1=André |last1=Kurs |first2=Aristeidis |last2=Karalis |first3=Robert |last3=Moffatt |first4=J. D. |last4=Joannopoulos |first5=Peter |last5=Fisher |first6=Marin |last6=Soljačić |title=Wireless Power Transfer via Strongly Coupled Magnetic Resonances |journal=Science |volume=317 |issue=5834 |date=6 July 2007 |pages=83–86 |doi=10.1126/science.1143254|pmid=17556549 |bibcode=2007Sci...317...83K |s2cid=17105396 |doi-access=free }}</ref><ref>{{cite journal |first1=Wenshen |last1=Zhou |first2=Shao Ying |last2=Huang |title=Novel coil design for wideband wireless power transfer |journal=2017 International Applied Computational Electromagnetics Society Symposium (ACES) |date= 28 September 2017 |pages=1–2 |url=https://ieeexplore.ieee.org/document/8051697}}</ref> varied-pitch solenoids for magnetic resonance imaging (MRI),<ref>{{cite journal |first1=Zhi Hua |last1=Ren |first2=Shao Ying |last2=Huang |title=The design of a short solenoid with homogeneous B1 for a low-field portable MRI scanner using genetic algorithm |journal=Proc. 26th ISMRM |date=August 2018 |pages=1720 |url=https://cds.ismrm.org/protected/18MPresentations/abstracts/1720.html }}{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> and non-cylindrical solenoids for other medical devices.<ref>{{cite journal |first1=L. |last1=Jian |first2=Y. |last2=Shi |first3=J. |last3=Liang |first4=C. |last4=Liu|first5=G. |last5=Xu|title=A Novel Targeted Magnetic Fluid Hyperthermia System Using HTS Coil Array for Tumor Treatment |journal=IEEE Transactions on Applied Superconductivity |volume=23 |issue=3 |date=June 2013 |pages=4400104 |doi=10.1109/TASC.2012.2230051|bibcode=2013ITAS...23Q0104J |s2cid=44197357 }}</ref>

The calculation of the intrinsic inductance and capacitance cannot be done using those for the conventional solenoids, i.e. the tightly wound ones. New calculation methods were proposed for the calculation of intrinsic inductance<ref>{{cite journal |first1=Wenshen |last1=Zhou |first2=Shao Ying |last2=Huang|title=An Accurate Model for Fast Calculating the Resonant Frequency of an Irregular Solenoid |journal=IEEE Transactions on Microwave Theory and Techniques |volume=67 |issue=7 |date= July 2019|pages=2663–2673|doi=10.1109/TMTT.2019.2915514|bibcode=2019ITMTT..67.2663Z |s2cid=182038533 }}</ref>(codes available at <ref>{{cite journal |first1=Wenshen |last1=Zhou |first2=Shao Ying |last2=Huang |title=the code for accurate model for fast calculating the resonant frequency of an irregular solenoid |date=12 April 2021 |url=https://github.com/wszhou/SRF_calculation}}</ref>) and capacitance.<ref>{{cite journal |first1=Wenshen |last1=Zhou |first2=Shao Ying |last2=Huang |title=Modeling the Self-Capacitance of an Irregular Solenoid |journal=IEEE Transactions on Electromagnetic Compatibility |date= October 2020 |volume=63 |issue=3 |pages=783–791 |doi=10.1109/TEMC.2020.3031075|issn=0018-9375|s2cid=229274298 }}</ref> (codes available at <ref>{{cite journal |first1=Wenshen |last1=Zhou |first2=Shao Ying |last2=Huang |title=the code for accurate model for self-capacitance of irregular solenoids |date=12 April 2021 |url=https://github.com/wszhou/capacitance_calc}}</ref>)