scholarly journals Cosmogenic activation of materials used in rare event search experiments

2016 ◽  
Vol 84 ◽  
pp. 62-69 ◽  
Author(s):  
C. Zhang ◽  
D.-M. Mei ◽  
V.A. Kudryavtsev ◽  
S. Fiorucci
2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Ze She ◽  
Zhi Zeng ◽  
Hao Ma ◽  
Qian Yue ◽  
Mingkun Jing ◽  
...  

AbstractRare event search experiments using germanium detectors are performed in underground laboratories to minimize the background induced by cosmic rays. However, the cosmogenic activation of cupreous detector components on the ground generates long half-life radioisotopes and contributes to the background level. We measured cosmogenic activation with 142.50 kg of copper bricks after 504 days of exposure at an altitude of 2469.4 m outside the China Jinping Underground Laboratory (CJPL). The specific activities of the cosmogenic nuclides produced in the copper bricks were measured using a low-background germanium gamma-ray spectrometer at CJPL. The production rates at sea level, in units of nuclei/kg/day, were $${18.6 \pm 2.0}$$ 18.6 ± 2.0 for $${^{54}}$$ 54 Mn, $${9.9 \pm 1.3}$$ 9.9 ± 1.3 for $${^{56}}$$ 56 Co, $${48.3 \pm 5.5}$$ 48.3 ± 5.5 for $${^{57}}$$ 57 Co, $${51.8 \pm 2.5}$$ 51.8 ± 2.5 for $${^{58}}$$ 58 Co, and $${39.7 \pm 5.7}$$ 39.7 ± 5.7 for $${^{60}}$$ 60 Co. The measurement will help to constrain cosmogenic background estimation for rare event searches using copper as a detector structure and shielding material. Based on the measured production rates, the impact of the cosmogenic background in cupreous components of germanium detectors on the next generation CDEX-100 experiment was assessed with the expected exposure history above ground.


Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 162
Author(s):  
Susana Cebrián

Double beta decay is a very rare nuclear process and, therefore, experiments intended to detect it must be operated deep underground and in ultra-low background conditions. Long-lived radioisotopes produced by the previous exposure of materials to cosmic rays on the Earth’s surface or even underground can become problematic for the required sensitivity. Here, the studies developed to quantify and reduce the activation yields in detectors and materials used in the set-up of these experiments will be reviewed, considering target materials like germanium, tellurium and xenon together with other ones commonly used like copper, lead, stainless steel or argon. Calculations following very different approaches and measurements from irradiation experiments using beams or directly cosmic rays will be considered for relevant radioisotopes. The effect of cosmogenic activation in present and future double beta decay projects based on different types of detectors will be analyzed too.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Ze She ◽  
Zhi Zeng ◽  
Hao Ma ◽  
Qian Yue ◽  
Mingkun Jing ◽  
...  

2010 ◽  
Vol 33 (5-6) ◽  
pp. 316-329 ◽  
Author(s):  
S. Cebrián ◽  
H. Gómez ◽  
G. Luzón ◽  
J. Morales ◽  
A. Tomás ◽  
...  

Author(s):  
J. Temple Black

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.


Author(s):  
W. R. Duff ◽  
L. E. Thomas ◽  
R. M. Fisher ◽  
S. V. Radcliffe

Successful retrieval of the television camera and other components from the Surveyor III spacecraft by the Apollo 12 astronauts has provided a unique opportunity to study the effects of a known and relatively extensive exposure to the lunar environment. Microstructural effects including those produced by micro-meteorite impact, radiation damage (by both the solar wind and cosmic rays) and solar heating might be expected in the materials used to fabricate the spacecraft. Samples received were in the form of 1 cm2 of painted unpainted aluminum alloy sheet from the top of the camera visor (JPL Code 933) and the sides (935,936) and bottom (934) of the lower camera shroud. They were prepared for transmission electron microscopy by first hand-grinding with abrasive paper to a thickness of 0.006". The edges were lacquered and the sample electropolished in 10% perchloric methanol using the “window” method, to a thickness of ~0.001". Final thinning was accomplished by polishing 3 mm punched disks in an acetic-phosphoric-nitric acid solution.


Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.


2011 ◽  
Author(s):  
Shu-cheng Steve Chi ◽  
Shu-chen Chen ◽  
Ray Friedman
Keyword(s):  

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