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High purity iron has recently received much attention as a new material with excellent characteristics. 1,2 The development of reliable analytical methods for the determination of trace impurity elements are required for production of pure iron. On the other hand, the use of scrap iron is increasing to make use of resources effectively and the accurate determination of various impurity metals in iron and steel is therefore essential for the quality control of iron products.The detection limit of lead by flame atomic absorption spectrometry (FAAS) is about 10 ng/ml. 3 Therefore the determination of traces of lead in high purity metals by FAAS usually requires its preconcentration, in addition to the separation of lead from matrix elements. Generally the blank value introduced from the reagents or from the laboratory environment must be kept at as low a level as possible in order to obtain the precise analytical results for traces of lead.Flow injection (FI) on-line preconcentration procedures now play an important role in trace metal analysis. They offer the possibility of determining lower analyte concentrations and avoiding matrix effects by separation of the analyte from interfering matrix components. Furthermore the consumption of time, sample and reagent, and the risk of contamination from the laboratory environment are low; the repeatability and efficiency are high compared with its corresponding batch counterpart procedures. [4][5][6][7] In this respect, FI systems combined with ion exchange or solid phase extraction techniques carried out in minicolumns have been successfully used in flame atomic absorption spectrometry (FAAS) because the preconcentrated analytes can be simply eluted into the nebulizer. [5][6][7][8] A large variety of highly efficient sorbents are usually used in on-line techniques for determination of trace metals, as reviewed by Yebra-Biurrum. 9 These sorbents include inorganic activated alumina; ion exchangers modified with complexing reagents; sorbents based on silica gel, naphthalene, styrenedivinylbenzene copolymers (XAD), and porous glass beads with immobilized chelates groups; reversed-phase silica sorbent (C18, C16 and C8); activated carbon; and chelating resins and celluloses. The typical chelating resin, Chelex-100, with iminodiacetate chelating groups has been among the most used. These sorbents are mostly used for determination of trace metal ions in natural water, biological samples, and food, but in some cases, these samples bring about difficulties if they contain large amounts of metal ions. For example, this problem gets complicated when trace elements are determined in complex metallic matrix samples such as waste water, alloys and rocks, because the column adsorbs not only micro components but also some matrix elements like iron, copper and others as well, and the sorbent capacity is insufficient.This work was undertaken to examine a Pb-selective chromatographic resin, 10 Pb·Spec TM (EIChrom Industries), to preconcentrate and separate lead from other sample matrix comp...

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We have been developing high-field accelerator magnets with the aim of upgrading the luminosity of the Large Hadron Collider. In this program, four kinds of Ta-matrix strands with slightly different cross-sectional structures (K1, K2, K3 and K4 strands) were designed and fabricated. The non-copper values of these strands were 700-800 at 15 T and 4.2 K. The cabling work of these strands was performed at Fermilab, and the superconducting properties of the cables were studied using the extracted strands from the cables. In this paper, we report on the fabrication experience for the strands and cables. The results obtained from this study are also presented.

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Research and development of copper stabilizedNb 3 Al strands and cables for a high field Nb 3 Al common coil magnet is ongoing with the cooperation of KEK-NIMS-Fermilab. In this work, newly designed K1 and K2 strands and cables were fabricated. The K1 strand used tantalum for the inter-filament matrix only and the K2 strand used it for the entire strand matrix. Wire breakage happened on the drawing of both precursors, and it may be caused by the de-bonding of the inter-filament as well as poorer cold-workability of the tantalum itself. Non Cu c 's at 12 T were 1,300 A mm 2 at 4.2 K and 1,600 A mm 2 at 1.9 K, an increase of about 20%. The low field magnetic instabilities at 4.2 K could be suppressed with K1 and K2 strands because of the tantalum inter-filament matrix. Similar superconducting characteristics were obtained on K1 and K2 strands. However, K2 strands showed excessive separation of the copper stabilizer when made into Rutherford cables, although K1 strands did not. The copper stabilizer prefers niobium as an interface material to obtain good bonding.

We have succeeded in making a superconducting Nb-Zr and V-Ti alloy multifilament wire using the diffusion reaction between constituent pure-metal subelements, which can omit the melt-and-casting step and may reduce the fabrication cost. A third element addition was also performed by replacing the constituent subelements with the third pure-metal subelement in the monofilament; Nb-Zr-V, Nb-Zr-Ti and V-Ti-Ta. Three kinds of heat treatment were investigated; (1) an alloying heat treatment (HT alloy ) which is carried out at the final size ('fs-HT alloy '), (2) HT alloy is followed by cold-working (W) down to the final size ('HT alloy + W'), and (3) an intermediate precipitation heat treatment (HT prec ) is carried out during the W stage coming after the HT alloy stage ('HT alloy + W + HT prec + W'). The 'HT alloy + W + HT prec + W' treatment was found to be most effective in enhancing the critical current densities for both Nb-68 at.% Zr and V-60 at.% Ti-9 at.% Ta alloys, despite the HT prec treatment having slightly degraded the critical magnetic field.