Authors:M. Brown, M. Tribelhorn, and M. Blenkinsop
Thermal analysis is routinely used to characterize pyrotechnic fuels, oxidants and fuel/oxidant mixtures . Thermomagnetometry
(TM) can provide additional information if the magnetic properties of the materials change during reaction. TG, TM and DTA
results for the iron/potassium permanganate, iron/barium peroxide, and iron/strontium peroxide systems as loose powders or
pressed pellets indicate predominantly solid-gas mechanisms for reactions in these systems.
atmosphere, which are more relevant for the production of superconducting layers, will be presented elsewere.
Ho(CH 3 COO) 3 · x H 2 O, Er(CH 3 COO) 3 ·4H 2 O, Tm(CH 3 COO) 3 · x H 2 O and Yb(CH 3 COO) 3 · x H 2 O all
Hydrogen sorption properties and some corresponding changes in the crystallization of amorphous TM33Zr67 (TM=Fe, Co, Ni) alloys have been investigated. Relatively large amount of hydrogen was found to dissolve into the amorphous alloys
during electrochemical hydrogen charging. The microstructural evolution during annealing of H-charged Ni33Zr67 was studied as well. The weaker bonded hydrogen desorbs in a large temperature range (440–625 K) before the crystallization
of the amorphous alloys to start. A hydride phase (ZrH2) was found to form during annealing the H-charged amorphous Ni33Zr67 alloy. During heating at constant heating rate the hydride decomposes at about 715 K and formation of Zr2Ni immediately takes place. The final microstructure of the Zr2Ni, crystallized from the H-charged matrix, is noticeably finer compared to the material crystallized from the H-free amorphous
alloy, most probably due to the higher temperature of Zr2Ni formation in the H-charged amorphous alloy than in the H-free sample.
LaRE(C 2 O 4 ) 3 · n H 2 O (RE = Dy, Ho, Er, Tm, Yb, Lu) and NdGd(C 2 O 4 ) 3 · n H 2 O samples were prepared by co-precipitation, as described in [ 6 ], starting from the commercial sesquioxides powders
A method for the production of167Tm using the165Ho(,2n)167Tm nuclear reaction and extraction-chromatography is described. The chemical recovery of Ho is >90%. The final product contains <4 g/ml of Ho with a radiochemical purity of >99% suitable for medical use. The estimated yield of167Tm is 10–20 Ci/A·h which is comparable with other recent work. Biodistributions of167Tm-citrate in mice indicate that167Tm is an ideal bone and liver tumor scanning agent.
Authors:Mahdi Sadeghi, Nadia Zandi, and Hossein Afarideh
In recent years, there has been a rapid expansion in the use of radio nuclides for therapeutic purposes. Thulium–167 is an
important radionuclide (T1/2 = 9.25 d) due to it could be used for tumor and bone studies in nuclear medicine. 167Tm complexed with hydroxy ethylene diamine tetra-acetic acid (HEDTA) could be used with the aim of bone imaging. 167Tm emits a prominent γ ray of 208 keV energy and low energy electrons. This study describes calculations on the excitation
functions of 165Ho(α,2n)167Tm, 167Er(p,n)167Tm, natEr(d,xn)167Tm and natEr(p,xn)167Tm reactions by ALICE/ASH (hybrid and GDH models) and TALYS-1.0 codes. In addition, calculated data by codes were compared
to experimental data that earlier were published and TENDL-2010 database. Moreover, optimal thickness of the targets and physical
yield were obtained by SRIM (stopping and range of ions in matter) code for each reaction. According to the results, the 167Er(p,n)167Tm and 165Ho(α,2n)167Tm reactions are suggested as the best method to produce 167Tm owing to minimum impurities. The TALYS-1.0 code, predict the maximum cross-section of about 382 mb at 11 MeV and 849 mb
at 26 MeV for 167Er(p,n)167Tm and 165Ho(α,2n)167Tm reactions, respectively. Finally, deposition of natEr2O3 on Cu substrate was carried out via the sedimentation method. The 516 mg of erbium(III)oxide with 103.2 mg of ethyl cellulose
and 8 mL of acetone were used to prepare a natEr2O3 layer of 11.69 cm2. 167Tm was produced via the natEr(p,n)167Tm nuclear process at 20 μA current and 15 → 7 MeV protons beam (1 h). Yield of about 3.2 MBq 167Tm per μA h were experimentally obtained.
By using a DSK of the French firm Seteram, the standard enthalpies of formation of 5 tellurites and 5 tetratellurites of the
rare earths Gd, Tb, Dy, Tm and Yb were determined for the first time.
Three parallel determinations for each sample were compared. The results are very similar, which is an indication of the great
reliability of the method used and the correctness of the data obtained.
Authors:V. Ramakrishna, S. Patil, L. Reddy, and A. Reddy
Extraction of Tm(III), from thiocyanate media, by different sulfoxides (R2SO) has revealed that the extractable complex is Tm(SCN)3·4 R2SO. When mixtures of DPSO and HTTA are used for the extraction of Tm(III) from thiocyanate or perchlorate media, synergistic
enhancement of the extraction of Tm(III) results. The complexes responsible for the enhanced extraction are Tm(TTA)3·DPSO and Tm(TTA)3·2 DPSO when perchlorate media were employed for the extraction and Tm(SCN)(TTA)2·2 DPSO and Tm(SCN)2(TTA)·3 DPSO, in addition to the above two when a thiocyanate medium was employed for the extraction. Values of equilibrium
constants for some equilibria encountered in the extraction of Am(III) and Tm(III) by mixtures of DPSO and HTTA are given.
Authors:J. Schwantes, W. Taylor, R. Rundberg, and D. Vieira
Approximately one curie of 171Tm (T1/2 = 1.92a) has been produced and purified for the purpose of making a nuclear target for the first measurements of its neutron
capture cross section. Target preparation consisted of three key steps: (1) material production; (2) separation and purification;
and (3) electrodeposition onto a suitable backing material. Approximately 1.5 mg of the target material (at the time of separation)
was produced by irradiating ca. 250 mg of its stable enriched 170Er lanthanide neighbour with neutrons at the ILL reactor in France. This production method resulted in a “difficult-to-separate”
1:167 mixture of near-neighboring lanthanides, Tm and Er. Separation and purification was accomplished using high-performance
liquid chromatography (HPLC), with a proprietary cation-exchange column (Dionex, CS-3) and alpha-hydroxyisobutyric acid (α-HIB)
eluent. This technique yielded a final product of ∼95% purity with respect to Tm. A portion (20 μg) of the Tm was electrodeposited
onto thin Be foil and delivered to the Los Alamos Neutron Science Center (LANSCE) for preliminary analysis of its neutron
capture cross section using the Detector for Advanced Neutron Capture Experiments (DANCE). This paper discusses the major
hurdles associated with the separation and purification step, including scale-up issues related to the use of HPLC for material
separation and purification of the target material from α-HIB and 4-(2-pyridylazo)resorcinol (PAR) colorant.