Development of a 0.5 T magnetic‐core alternating‐field demagnetizer
Development of a 0.5 T magnetic‐core alternating‐field demagnetizer
复制标题
0.5T磁芯交变场退磁机的研制
DOI：
10.1002/2015gc006204
复制
发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
D. Finn
中科院分区：
文献类型：
--
作者：
W. Schillinger;E. R. Morris;R. S. Coe;D. Finn
我们已经构建了一个交流磁场（AF）退磁器，其磁芯位于被动空气冷却线圈中，可以在高达0.5 T的磁场下正常工作，几乎是我们之前在商业仪器中所能达到的3倍。该磁场由商用1 kW功率放大器供电，横向于钻孔，在25 mm古地磁样品上均匀至±2%，并与我们现有的样品处理器兼容，用于自动退磁和测量。偶次谐波小于等于基波的1 ppm，因此产生的无滞后剩磁可以忽略不计。高得多的峰值交变磁场，分别是空芯螺线管和亥姆霍兹线圈配置中通常可用的2倍和5倍，使得许多无法用市售设备完全退磁的样品能够成功AF退磁。这种能力对于高磁化率的沉积岩和火成岩以及含有在热退磁过程中发生变化的磁性矿物的地外物质特别有用。除了给我们自己的研究带来的好处之外，该仪器还带来了更广泛的潜在影响，即它可以取代目前使用的大多数自动AF退磁系统的横向线圈，无论是用于离散还是连续U通道测量，其通常限于100 mT的峰值场。手动和翻滚消磁器也将受益于最大磁场比商业螺线管线圈所能达到的最大磁场增加102倍。此外，我们预计它和类似设计的磁芯仪器将能够获得更高的磁场，达到1T量级。
We have constructed an alternating‐field (AF) demagnetizer with a magnetic core in a passively air‐cooled coil that can routinely operate at fields up to 0.5 T, almost 3 times higher than we could attain before in our commercial instrument. The field is powered by a commercial 1 kW power amplifier and is transverse to the bore, uniform to ±2% over a 25 mm paleomagnetic sample, and compatible with our existing sample handler for automated demagnetization and measurement. Even harmonics are ≤1 ppm of the fundamental and so generate negligible anhysteretic remanence. The much higher peak alternating field, 2 and 5 times that commonly available in air‐core solenoidal and Helmhotz coil configurations, respectively, enables successful AF demagnetization of many samples that could not be completely demagnetized with commercially available equipment. This capability is especially useful for high‐coercivity sedimentary and igneous rocks and extraterrestrial materials that contain magnetic minerals that alter during thermal demagnetization. In addition to the benefits, this instrument brings to our own research, a much broader potential impact is that it could replace the transverse coils of most automated AF demagnetization systems in use today, whether for discrete or continuous U‐channel measurements, which are commonly limited to peak fields of ∼100 mT. Manual and tumbling demagnetizers would benefit as well by the ∼2 times increase in maximum field over those that can be attained by commercial solenoidal coils. Furthermore, we expect that it and similarly designed magnetic‐core instruments will be capable of attaining even higher fields, of order 1 T.
蛇河平原流纹岩灰长岩的磁各向异性：利用火山岩剩磁进行对比、古地磁研究和地质重建的意义
影响因子：
3.4
作者：
Finn D
通讯作者：
Finn D
SushiBar：古地磁研究自动化系统
影响因子：
3.7
作者：
S.A. Gilder
通讯作者：
S.A. Gilder