We have determined the production yields for radionuclides in Al
2O
3, SiO
2, S, Ar, K
2SO
4, CaCO
3, Fe, Ni and Cu targets, which were irradiated with slow negative muons at the Paul Scherrer ...Institute in Villigen (Switzerland). The fluences of the stopped negative muons were determined by measuring the muonic X-rays. The concentrations of the long-lived and short-lived radionuclides were measured with accelerator mass spectrometry (AMS) and γ-spectroscopy, respectively. Special emphasis was put on the radionuclides
10Be,
14C and
26Al produced in quartz targets,
26Al in Al
2O
3 and S targets,
36Cl in K
2SO
4 and CaCO
3 targets, and
53Mn in Fe
2O
3 targets. These targets were selected because they are also the naturally occurring target minerals for cosmic ray interactions in typical rocks. We also present results of calculations for depth-dependent production rates of radionuclides produced after cosmic ray μ
− capture, as well as cosmic ray-induced production rates of geologically relevant radionuclides produced by the nucleonic component, by μ
− capture, by fast muons and by neutron capture.
To investigate muon-induced nuclear reactions leading to the production of radionuclides, targets made of C
9H
12, SiO
2, Al
2O
3, Al, S, CaCO
3, Fe, Ni, Cu, Gd, Yb and Tl were irradiated with 100 ...and 190 GeV muons in the NA54 experimental setup at CERN. The radionuclide concentrations were measured with accelerator mass spectrometry and γ-spectroscopy. Results are presented for the corresponding partial formation cross-sections. Several of the long-lived and short-lived radionuclides studied are also produced by fast cosmic ray muons in the atmosphere and at depths underground. Because of their importance to earth sciences investigations, calculations of the depth dependence of production rates by fast cosmic ray muons have been made.
The production of radioactive isotopes in scintillation detectors by muons and their secondary shower particles has been studied experimentally at the SPS muon beam at CERN. This paper shows the ...results obtained in cross-section measurements on liquid scintillator targets, especially on
12C which is the most relevant target in these organic materials. Their energy dependence has been deduced from the cross-sections determined at two muon energies 100 and 190 GeV. Based on the measured cross-sections the muon-induced background rates for the forthcoming solar neutrino experiments BOREXINO and KAMLAND have been calculated for different energy regions that are relevant for solar neutrino physics.
Experimental data for the cosmogenic in situ production of radionuclides and its depth dependence are used for two applications, the determination of exposure ages and of erosion rates. ...Concentrations of the long-lived radionuclides
10Be,
14C and
26Al in quartz are presented as function of exposure age, depth before exposure and erosion rate after exposure. It is shown that the cosmogenic production before exposure can introduce important corrections to the representation without consideration of pre-exposure production. Depth profiles of
10Be,
14C and
26Al in quartz and sulfur, of
36Cl in K
2O, CaCO
3, granite and concrete and of
53Mn in Fe
2O
3 are given as function of erosion rate. Consequences to determinations of neutron fluences in Hiroshima are discussed.
In-situ production of radionuclides at great depths Heisinger, B.; Niedermayer, M.; Hartmann, F.J. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
03/1997, Letnik:
123, Številka:
1-4
Journal Article
Recenzirano
The depth dependent in-situ production of radionuclides has been measured and calculated taking into account spallation reactions, reactions with captured negative and fast muons and background ...reactions. The following probabilities f∗ of particle emission channels after μ− capture have been measured:O(μ−,νμαpxn)10Be, x = 1–3, f∗ = (5.2 ± 0.6) × 10−3 and S(μ−,νμαxn)26Al, x = 2–4, 6, f∗ = (1.4 ± 0.4) × 10−3. From the oxygen irradiation result for 10Be and the known channel probability from silicon to 26Al, the production ratio of 26Al to 10Be after μ− capture in quartz has been deduced to be P(26Al)P(10Be) = 7.2 ± 1.2. The nucleon emission probabilities after μ− capture have been determined for iron. The particle emission channel Fe(μ−,νμxn)53Mn, x = 1, 3–5 was estimated to 0.05 ± 0.02. Natural depth profiles of 26Al in quartz have been measured in Northern Bavaria up to depths of 250 m and have been compared with calculated profiles taking erosion into account. From this comparison, the erosion rate in the last million years has been obtained to be about 10–20 μm/y.
American Minimalism in the 1980s Heisinger, Brent
American music (Champaign, Ill.),
12/1989, Letnik:
7, Številka:
4
Journal Article
Recenzirano
The authenticity and viability of minimal music has been hotly debated by musicians and critics, but it has undeniably become a genuine segment of mainstream contemporary music. Minimalism and its ...proponents are discussed.
Medical application of 26Al Steinhausen, C.; Gerisch, P.; Heisinger, B. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
6/1996, Letnik:
113, Številka:
1
Journal Article
Recenzirano
Accelerator mass spectrometry (AMS) measurements with
26Al as tracer were performed in order to study the aluminium metabolism and anomalies in the human body and in rats. In particular, the ...differences between healthy volunteers and patients with renal failure were investigated. The obtained data points of
26Al in blood and urine were described by an open compartment model with three peripheral compartments. It was found that the minimum of peripheral compartments needed to describe
26Al concentrations in blood and urine over a time period of three years is at least three.
Medical application of super(26)Al Steinhausen, C; Gerisch, P; Heisinger, B ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
01/1996, Letnik:
113, Številka:
1-4
Journal Article
Recenzirano
Accelerator mass spectrometry (AMS) measurements with super(26)Al as tracer were performed in order to study the aluminium metabolism and anomalies in the human body and in rats. In particular, the ...differences between healthy volunteers and patients with renal failure were investigated. The obtained data points of super(26)Al in blood and urine were described by an open compartment model with three peripheral compartments. It was found that the minimum of peripheral compartments needed to describe super(26)Al concentrations in blood and urine over a time period of three years is at least three.
