Chemical Analysis of the Moon at the Surveyor V Landing Site

Turkevich, A.; Franzgrote, Ernest J.; Patterson, J. Herbert

doi:10.1126/science.158.3801.635

Cited by 109 publications

(22 citation statements)

References 5 publications

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“…Table 1 shows a typical Uncertainty Budget for this analysis which includes a number of secondary effects as well as effects of spectral distortion. Counting statistics (A 1 & A 2 ) should not dominate these types of measurements, and we list ten other effects (A 3-6 & B [1][2][3][4][5][6] ) most of which are not usually considered when estimating experimental uncertainties in measurements of this type. We discuss these in turn :-…”

Section: Methodsmentioning

confidence: 99%

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High accuracy traceable Rutherford backscattering spectrometry of ion implanted samples

Colaux

Jeynes

2014

Anal. Methods

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There are few techniques capable of the non-destructive and model-free measurement at 1% absolute accuracy of quantity of material in thin films without the use of sample-matched standards. We demonstrate that Rutherford backscattering spectrometry can achieve this robustly, reliably and conveniently. Using 1.5 MeV He + , a 150 keV ion implant into silicon with a nominal fluence of 5 × 10 15 As/cm² has been independently measured repeatedly over a period of 2 years with a mean total combined standard uncertainty of 0.9 ± 0.3% relative to an internal standard given by the silicon stopping power (a coverage factor k=1 is used for all uncertainties given). The stopping power factor of this beam in silicon is determined absolutely with a mean total combined standard uncertainty of 0.8 ± 0.1%, traceable to the 0.6% uncertainty of the Sb-implanted certified reference material (CRM) from IRMM, Geel. The uncertainty budget highlights the need for the accurate determination of the electronic gain of the detection system and the scattering angle, parameters conventionally regarded as trivial. This level of accuracy is equally applicable to much lower fluences since it is not dominated by any one effect; but it cannot be reached without good control of all of these effects. This analytical method is extensible to non-Rutherford scattering. The stopping power factor of 4.0 MeV lithium in silicon is also determined at 1.0% absolute accuracy traceable to the Sb-implanted CRM. This work used SRIM2003 stopping powers which are therefore demonstrated correct at 0.8% for 1.5 MeV He in Si and 1% for 4 MeV Li in Si.

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Section: Methodsmentioning

confidence: 99%

“…See text for discussion of A i and B i . The reduced uncertainty (U 5 ; this is the measurement precision shown in Figure 2) for a given beam is given by U 4 less the systematic contributions (B 3-6 & A [5][6] ) in quadrature. The error bars are given as the "reduced uncertainty" (U 5 , k=1; see Table 1).…”

Section: Tablesmentioning

confidence: 99%

High accuracy traceable Rutherford backscattering spectrometry of ion implanted samples

Colaux

Jeynes

2014

Anal. Methods

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“…The structure of thin films involving polymer blends also have many important applications, and the mixing profiles can be systematically followed by deuterating one polymer and profiling the deuterium by 3 He-NRA [28]. Alternatively, a deuterium primary beam can be used to simultaneously profile specific isotopes using NRA, for example 12 PIXE analyses typically use a 3 MeV proton microbeam : elastic backscattering cross-sections are non-Rutherford for 2 MeV protons on all targets of mass up to at least Fe. This is one good reason why historically PIXE and RBS/EBS spectra were usually analysed completely separately: the ESS spectra, involving complicated and poorly-known cross-sections, were considered practically intractable in general by the PIXE community.…”

Section: Iba Methods and Perspectivesmentioning

confidence: 99%

“…Claims for a 1% accuracy for RBS have often been made -a notable early example is the report by Turkovich et al on the analysis of moon rocks by Surveyor V in 1967 [12] -but these claims have never been supported by a critical analysis of the uncertainty budget: indeed, uncertainty budgets are still not widely used in IBA [1]. Here we will critically review previous RBS work applicable to the determination of the quantity of material in thin films at a high traceable accuracy, and also critically review the methods required to apply RBS traceably at this accuracy.…”

Section: Introductionmentioning

confidence: 99%

Accurate Determination of Quantity of Material in Thin Films by Rutherford Backscattering Spectrometry

2012

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Ion beam analysis (IBA) is a cluster of techniques including Rutherford and non-Rutherford backscattering spectrometry, and particle-induced X-ray emission (PIXE). Recently, the ability to treat multiple IBA techniques (including PIXE) self-consistently has been demonstrated. The utility of IBA for accurately depth profiling thin films is critically reviewed. As an important example of IBA, three laboratories have independently measured a silicon sample implanted with a fluence of nominally 5.1015As/cm2 at an unprecedented absolute accuracy. Using 1.5 MeV 4He+ Rutherford backscattering spectrometry (RBS), each lab has demonstrated a combined standard uncertainty around 1% (coverage factor k=1) traceable to an Sb-implanted certified reference material through the silicon electronic stopping power. The uncertainty budget shows that this accuracy is dominated by the knowledge of the electronic stopping, but that special care must also be taken to accurately determine the electronic gain of the detection system and other parameters. This RBS method is quite general and can be used routinely, to accurately validate ion implanter charge collection systems, to certify SIMS standards, and for other applications. The generality of application of such methods in IBA is emphasised: if RBS and PIXE data are analysed self-consistently then the resulting depth profile inherits the accuracy and depth resolution of RBS and the sensitivity and elemental discrimination of PIXE

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“…The demonstration by Turkevich et al (12) that the surface regions of the moon were highly differentiated, and the subsequent confirmations of these results by the analyses of samples from the Apollo 11 and Apollo 12 missions, showed that both titaniferous basalt and anorthosite were present on the lunar surface; thus, a modification of previous ideas in regard to lunar structure was required. A model of a melted surface layer and a cool interior for the early structure of the moon was adopted (13).…”

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confidence: 98%

Was the Moon Originally Cold?

Urey

1971

Science

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In recent reports (I ) the term racemization is used inappropriately.It is stated in both reports that Lisoleucine racemizes to D-alloisoleucine. This reaction is epimerization, not racemization. Racemization of L-iSOleucine results in the formation of DLisoleucine. As stated in Eliel (2): "'racemization is the process of producing a racemic modification starting with one of the pure enantiomers."

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Chemical Analysis of the Moon at the Surveyor V Landing Site

Cited by 109 publications

References 5 publications

High accuracy traceable Rutherford backscattering spectrometry of ion implanted samples

High accuracy traceable Rutherford backscattering spectrometry of ion implanted samples

Accurate Determination of Quantity of Material in Thin Films by Rutherford Backscattering Spectrometry

Was the Moon Originally Cold?

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