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Ultracold neutron detectors based on (10)B converters used in the qBounce experiments.

Jenke T, Cronenberg G, Filter H, Geltenbort P, Klein M, Lauer T, Mitsch K, Saul H, Seiler D, Stadler D, Thalhammer M, Abele H - Nucl Instrum Methods Phys Res A (2013)

Bottom Line: The mentioned experiments utilize a beam-monitoring concept which accounts for variations in the neutron flux that are typical for nuclear research facilities.The converter can also be used for detectors, which feature high efficiencies paired with high spatial resolution of [Formula: see text].They allow one to resolve the quantum mechanical wave function of an ultracold neutron bound in the gravity potential above a neutron mirror.

View Article: PubMed Central - PubMed

Affiliation: Atominstitut TU Wien, Stadionallee 2, 1020 Wien, Austria.

ABSTRACT

Gravity experiments with very slow, so-called ultracold neutrons connect quantum mechanics with tests of Newton's inverse square law at short distances. These experiments face a low count rate and hence need highly optimized detector concepts. In the frame of this paper, we present low-background ultracold neutron counters and track detectors with micron resolution based on a (10)B converter. We discuss the optimization of (10)B converter layers, detector design and concepts for read-out electronics focusing on high-efficiency and low-background. We describe modifications of the counters that allow one to detect ultracold neutrons selectively on their spin-orientation. This is required for searches of hypothetical forces with spin-mass couplings. The mentioned experiments utilize a beam-monitoring concept which accounts for variations in the neutron flux that are typical for nuclear research facilities. The converter can also be used for detectors, which feature high efficiencies paired with high spatial resolution of [Formula: see text]. They allow one to resolve the quantum mechanical wave function of an ultracold neutron bound in the gravity potential above a neutron mirror.

No MeSH data available.


Beam-monitor concept. At the juncture of two neutron beam guides leading to the experiment, losses occur proportional to the incoming flux. We monitor part of these losses by means of an additional counter (adapted from: [22, Fig. 2.11, p. 23]).
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f0045: Beam-monitor concept. At the juncture of two neutron beam guides leading to the experiment, losses occur proportional to the incoming flux. We monitor part of these losses by means of an additional counter (adapted from: [22, Fig. 2.11, p. 23]).

Mentions: The incoming neutron flux at a beam position at a nuclear research reactor is subject to fluctuations. This effect is accounted for by normalizing all measured count rates by a measure linearly proportional to the incoming flux. Fig. 9 shows our beam monitor setup. We take advantage of the unavoidable losses occurring at the junction between two neutron beam guides leading to the experiment. These losses are proportional to the incoming flux and are monitored by an additional time-resolving neutron counter. The measured beam monitor count rate is in the order of 100 s−1, which is several orders of magnitude larger than the observed count rates in our experiments. The beam monitor is read out by the same read-out system used for the experiment detector.


Ultracold neutron detectors based on (10)B converters used in the qBounce experiments.

Jenke T, Cronenberg G, Filter H, Geltenbort P, Klein M, Lauer T, Mitsch K, Saul H, Seiler D, Stadler D, Thalhammer M, Abele H - Nucl Instrum Methods Phys Res A (2013)

Beam-monitor concept. At the juncture of two neutron beam guides leading to the experiment, losses occur proportional to the incoming flux. We monitor part of these losses by means of an additional counter (adapted from: [22, Fig. 2.11, p. 23]).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4375608&req=5

f0045: Beam-monitor concept. At the juncture of two neutron beam guides leading to the experiment, losses occur proportional to the incoming flux. We monitor part of these losses by means of an additional counter (adapted from: [22, Fig. 2.11, p. 23]).
Mentions: The incoming neutron flux at a beam position at a nuclear research reactor is subject to fluctuations. This effect is accounted for by normalizing all measured count rates by a measure linearly proportional to the incoming flux. Fig. 9 shows our beam monitor setup. We take advantage of the unavoidable losses occurring at the junction between two neutron beam guides leading to the experiment. These losses are proportional to the incoming flux and are monitored by an additional time-resolving neutron counter. The measured beam monitor count rate is in the order of 100 s−1, which is several orders of magnitude larger than the observed count rates in our experiments. The beam monitor is read out by the same read-out system used for the experiment detector.

Bottom Line: The mentioned experiments utilize a beam-monitoring concept which accounts for variations in the neutron flux that are typical for nuclear research facilities.The converter can also be used for detectors, which feature high efficiencies paired with high spatial resolution of [Formula: see text].They allow one to resolve the quantum mechanical wave function of an ultracold neutron bound in the gravity potential above a neutron mirror.

View Article: PubMed Central - PubMed

Affiliation: Atominstitut TU Wien, Stadionallee 2, 1020 Wien, Austria.

ABSTRACT

Gravity experiments with very slow, so-called ultracold neutrons connect quantum mechanics with tests of Newton's inverse square law at short distances. These experiments face a low count rate and hence need highly optimized detector concepts. In the frame of this paper, we present low-background ultracold neutron counters and track detectors with micron resolution based on a (10)B converter. We discuss the optimization of (10)B converter layers, detector design and concepts for read-out electronics focusing on high-efficiency and low-background. We describe modifications of the counters that allow one to detect ultracold neutrons selectively on their spin-orientation. This is required for searches of hypothetical forces with spin-mass couplings. The mentioned experiments utilize a beam-monitoring concept which accounts for variations in the neutron flux that are typical for nuclear research facilities. The converter can also be used for detectors, which feature high efficiencies paired with high spatial resolution of [Formula: see text]. They allow one to resolve the quantum mechanical wave function of an ultracold neutron bound in the gravity potential above a neutron mirror.

No MeSH data available.