Experimental Validation of the Selection Field of a Rabbit-Sized FFL Scanner
| Autor: | Bakenecker, Anna, Friedrich, Thomas, Von Gladiss, Anselm, Graeser, Matthias, Stelzner, Jan, Buzug, Thorsten M. |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: | |
| DOI: | 10.18416/ijmpi.2017.1703013 |
| Popis: | There are two different field topologies in magnetic particle imaging which enable the spatial encoding of the signal. Scanners using a field-free line (FFL) are promising regarding their sensitivity, because the low field volume is larger compared to a field-free point (FFP) and therefore, more particles contribute to the signal. A rabbit-sized FFL scanner with a bore diameter of 180 mm was presented in 2014. After planning and assembling the scanner an experimental validation of the designated field topology of the selection field is presented. With a hall probe the field topologies of the z-gradient coil and the two quadrupole coils forming together the selection field of the scanner were investigated. These magnetic field measurements show the expected field topologies: an FFP formed by the z-gradient coil and an FFL parallel to the bore of the scanner formed by each quadrupole coil. From these measurements the field gradients were calculated and approximated towards their designated currents. The results are in good agreement with the expected field gradients. Since power losses in the shielding occur for higher frequencies and the power transmission of the transformer is problematic for low frequencies, the best suitable frequency for rotating the FFL was evaluated. 20 Hz is chosen as it represents the best compromise between transformer performance and power loss in the shielding. International Journal on Magnetic Particle Imaging, Vol.3, No.1, Article ID 1703013 |
| Databáze: | OpenAIRE |
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