Surface characterization of diamond-like carbon for ultracold neutron storage

Atchison, F.; Bergmaier, A.; Daum, M.; Döbeli, M.; Dollinger, G.; Fierlinger, P.; Foelske, Annette; Henneck, R.; Heule, S.; Kasprzak, M.; Kirch, K.; Knecht, A.; Kuźniak, M.; Pichlmaier, A.; Schelldorfer, R.; Zsigmond, G.

doi:10.1016/j.nima.2007.12.037

Cited by 9 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of dPS, where one expects an extremely low loss factor (W/V f = 0.0016 × 10 −4 ), the difference is three orders of magnitude. This difference, previously termed anomalous losses, is attributed to, e.g., impurities, low-energy heating, surface contaminations or microscopic holes in the coating, and contaminations of the surface with hydrogen [65][66][67]96,97]. The data also show that there is no dependence on energy, as expected.…”

Section: B the Wall Loss Parameter ηsupporting

confidence: 67%

“…Their optical potentials, V f , and other material parameters were determined [59]: V f (dPS) = (161 ± 10) neV and V f (dPE) = (214 ± 10) neV. The UCN losses at room temperature for dPS, η = (3 ± 1) × 10 −4 [59], were similar to those of commonly used materials for UCN storage, e.g., diamond-like carbon (DLC) or beryllium [48] with optical potentials around 250 neV [46,48,49,[60][61][62][63] and low losses [52,[64][65][66][67]. In the nEDM experiment at PSI [7], the high-voltage electrodes of the present chamber are coated with DLC while the walls are coated with dPS, which has the limiting optical potential V f of the apparatus.…”

Section: Ucn Losses and Depolarization From Surfacesmentioning

confidence: 91%

See 1 more Smart Citation

Losses and depolarization of ultracold neutrons on neutron guide and storage materials

et al. 2017

Self Cite

View full text Add to dashboard Cite

At Institut Laue-Langevin (ILL) and Paul Scherrer Institute (PSI), we have measured the losses and depolarization probabilities of ultracold neutrons on various materials: (i) nickel-molybdenum alloys with weight percentages of 82/18, 85/15, 88/12, 91/9, and 94/6 and natural nickel Ni100, (ii) nickel-vanadium NiV93/7, (iii) copper, and (iv) deuterated polystyrene (dPS). For the different samples, storage-time constants up to ∼460 s were obtained at room temperature. The corresponding loss parameters for ultracold neutrons, η, varied between 1.0 × 10 −4 and 2.2 × 10 −4 . All η values are in agreement with theory except for dPS, where anomalous losses at room temperature were established with four standard deviations. The depolarization probabilities per wall collision β measured with unprecedented sensitivity varied between 0.7 × 10 −6 and 9.0 × 10 −6 . Our depolarization result for copper differs from other experiments by 4.4 and 15.8 standard deviations. The β values of the paramagnetic NiMo alloys over molybdenum content show an increase of β with increasing Mo content. This is in disagreement with expectations from literature. Finally, ferromagnetic behavior of NiMo alloys at room temperature was found for molybdenum contents of 6.5 at.% or less and paramagnetic behavior for more than 8.7 at.%. This may contribute to solving an ambiguity in literature.

show abstract

Section: B the Wall Loss Parameter ηsupporting

confidence: 67%

Section: Ucn Losses and Depolarization From Surfacesmentioning

confidence: 91%

Losses and depolarization of ultracold neutrons on neutron guide and storage materials

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…The Nocado tubes used have an inner diameter of 66 mm. At the end of the guides, the UCN enter the prestorage vessel through a stainless steel adapter flange mounted on customized vacuum shutters, special DIN-200 shutters from VAT 3 with inside parts coated with diamond-like carbon [19,[23][24][25] (see Sec.2.3). These shutters were later installed as beam ports of the PSI UCN source.…”

Section: Methodsmentioning

confidence: 99%

A prestorage method to measure neutron transmission of ultracold neutron guides

Blau

Daum

Fertl

et al. 2016

Nuclear Instruments and Methods in Physics Research Section A:

Self Cite

View full text Add to dashboard Cite

show abstract

“…which was found to have excellent UCN storage properties [47][48][49][50][51][52]. The thickness of the DLC coating varied between 1 and 2 µm depending on position during the coating process.…”

Section: Ucn Storage Vesselmentioning

confidence: 99%

Neutron optics of the PSI ultracold-neutron source: characterization and simulation

et al. 2020

Self Cite

View full text Add to dashboard Cite

The ultracold neutron (UCN) source at the Paul Scherrer Institute serves mainly experiments in fundamental physics. High UCN intensities are the key for progress and success in such experiments.A detailed understanding of all source parameters is required for future improvements. Here we present the UCN source components, elements of the neutron optics, the characterization of important related parameters like emptying times, storage times or transmission probabilities of UCN which are ultimately defining the UCN intensity delivered at the beamports. We also introduce a detailed simulation model of the PSI UCN source, used to analyze the measurements and to extract surface parameters.

show abstract

Surface characterization of diamond-like carbon for ultracold neutron storage

Cited by 9 publications

References 24 publications

Losses and depolarization of ultracold neutrons on neutron guide and storage materials

Losses and depolarization of ultracold neutrons on neutron guide and storage materials

A prestorage method to measure neutron transmission of ultracold neutron guides

Neutron optics of the PSI ultracold-neutron source: characterization and simulation

Contact Info

Product

Resources

About