论文标题
$^3 $ HE $^+$磁矩的直接测量
Direct measurement of the $^3$He$^+$ magnetic moments
论文作者
论文摘要
如今，Helium-3已成为基本物理学研究[1、2、3]，核和原子结构[4、5]，磁化测定和计量[6]以及化学和医学[7、8]的最重要候选者之一。特别是，已经提出了$^3 $ HE核磁共振（NMR）探针作为绝对磁力测定法的新标准[6，9]。这需要$^3 $ HE核磁矩的高临界值，但是，到目前为止，这仅是间接确定的，相对精确度为每比隆（P.P.B.）$ 12 $零件[10,11]。在这里，我们调查了$^3 $^$^+$地面超精细结构在笔架陷阱中直接测量$^3 $^3 $^3 $^he $^+$^+$^+$ g'_i = -4.255 \，099 \，606 \，606 \，9（30）_ {stat） hfs}^{\ rm exp} = - 8 \，665 \，649 \，865.77（26）_ {stat}（1）_ {sys} $ hz和绑定的电子$ g $ g $ - factor $ g_e^e^e^^expector $ g_e^\ exp {exp {exp} 79（34）_ {stat}（30）_ {sys} $。后者与我们的理论值$ g_e^\ text {theo} = - 2.002 \，177 \，416 \，252 \，23（39）$基于[12]的参数和基本常数。我们对$^3 $ He $^+$ uno $ g $ factor的测量值允许确定裸核的$ g $ factor $ g_i = -4.255 \，250 \，699 \，699 \，7（30）_ {stat} _ {stat}}（17）_ {sys}（sys}（sys}（sys}（sys}） [13] $σ_ {^3he^+} = 0.000 \，035 \，507 \，38（3）$。与以前的间接结果相比，这构成了$^3 $ he nmr探针的第一个直接校准，并提高了一个数量级的精度。与以前的最精确值相比，测得的零场超精细分裂可提高两个数量级[14]，并使我们能够确定Zemach Radius [15]至$ r_z = 2.608（24）$ FM。
Helium-3 has nowadays become one of the most important candidates for studies in fundamental physics [1, 2, 3], nuclear and atomic structure [4, 5], magnetometry and metrology [6] as well as chemistry and medicine [7, 8]. In particular, $^3$He nuclear magnetic resonance (NMR) probes have been proposed as a new standard for absolute magnetometry [6, 9]. This requires a high-accuracy value for the $^3$He nuclear magnetic moment, which, however, has so far been determined only indirectly and with a relative precision of $12$ parts per billon (p.p.b.) [10,11]. Here we investigate the $^3$He$^+$ ground-state hyperfine structure in a Penning trap to directly measure the nuclear $g$-factor of $^3$He$^+$ $g'_I=-4.255\, 099\, 606\, 9(30)_{stat}(17)_{sys}$, the zero-field hyperfine splitting $E_{\rm HFS}^{\rm exp}=-8\, 665\, 649\, 865.77(26)_{stat}(1)_{sys}$ Hz and the bound electron $g$-factor $g_e^\text{exp}=-2.002\, 177\, 415\, 79(34)_{stat}(30)_{sys}$. The latter is consistent with our theoretical value $g_e^\text{theo}=-2.002\, 177\, 416\, 252\, 23(39)$ based on parameters and fundamental constants from [12]. Our measured value for the $^3$He$^+$ nuclear $g$-factor allows for the determination of the $g$-factor of the bare nucleus $g_I=-4.255\, 250\, 699\, 7(30)_{stat}(17)_{sys}(1)_{theo}$ via our accurate calculation of the diamagnetic shielding constant [13] $σ_{^3He^+}=0.000\,035\,507\,38(3)$. This constitutes the first direct calibration for $^3$He NMR probes and an improvement of the precision by one order of magnitude compared to previous indirect results. The measured zero-field hyperfine splitting improves the precision by two orders of magnitude compared to the previous most precise value [14] and enables us to determine the Zemach radius [15] to $r_Z=2.608(24)$ fm.
