Radiation detection with the pyromagnetic effect
Radiation detection with the pyromagnetic effect
复制标题
利用热磁效应进行辐射检测
DOI：
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发表时间：
1971
期刊：
影响因子：
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通讯作者：
R. E. Caruthers
中科院分区：
文献类型：
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作者：
R. Walser;R. Bene;R. E. Caruthers
用Chynoweth [1]最初描述的方法测量了几种在300°K附近发生磁相变的材料的动态热磁响应。结果表明，在快速动态热模式下工作的实用宽带热磁辐射探测器是可能的。最好的结果是用钆和锰锗化物晶体获得的，它们具有略低于300°K的二级磁相变。它们的响应在300°K时达到峰值，但在相当大的温度范围内仍然很高，在钆的情况下为25°C。用钆探测器获得的NEP为10- 8 W·Hz-1/2（0.12 cm 2有效面积），比300°K热释电探测器的NEP大10倍，但受到探测器线圈中实验室噪声拾取的限制，而不是内部约翰逊噪声的限制。改进的技术应导致较低的NEP。在临界温度下的两种材料的一阶磁相变，FeRh和MnAs的热磁响应，大大小于预期。与静态磁化测量的阶跃相比，它们也是非常不连续的。第三种材料，Fe .71 Mn 1.44 As，在344°K下具有一级跃迁，给出了更大的响应，但在非常窄的温度范围内。
The dynamic pyromagnetic response of several materials with magnetic phase transitions near 300°K has been measured by a method initially described by Chynoweth [1]. The results indicate that practical broad-band pyromagnetic radiation detectors operating in a fast dynamic thermal mode are possible. The best results were obtained with gadolinium and manganese germanide crystals which have second-order magnetic phase transitions slightly below 300°K. Their responses peaked at 300°K, but remained high over fairly large temperature ranges, a 25°C interval in the case of gadolinium. The NEP of ∼ 10-8W.Hz-1/2(0.12 cm2active area) obtained with gadolinium is larger by a factor of 10 than that reported for 300°K pyroelectric detectors, but was limited by laboratory noise pickup in the detector coil rather than the internal Johnson noise. Improved techniques should result in lower NEPs. The pyromagnetic responses at the critical temperatures of two materials with first-order magnetic phase transitions, FeRh and MnAs, were considerably smaller than expected. They were also anomalously discontinuous compared with the measured step in the static magnetization. A third material, Fe .71 Mn 1.44 As, with a first-order transition at 344°K, gave a much larger response, but over a very narrow temperature range.