A circulating hydrogen ultra-high purification system for the MuCap experiment

Ganzha, V. A.; Кравцов, П.; Maev, O.; Schapkin, G. N.; Semenchuk, G. G.; Trofimov, V.; Vasilyev, A.; Взнуздаев, М.; Clayton, Steven; Kammel, P.; Kiburg, B.; Hildebrandt, M.; Petitjean, C.; Banks, Thomas; Lauss, B.

doi:10.1016/j.nima.2007.06.010

Cited by 26 publications

(10 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ultra-pure target gas: Target purity of ∼ 10 ppb was maintained with a continuous circulation and filter system [92]. The TPC allowed in-situ monitoring of impurities by observing charged nuclear recoils from µ − + O → ν µ + N * , in the rare cases of muon transfer to impurities, occuring at the 10 −5 level.…”

Section: Mucap Experiment: Strategy and Resultsmentioning

confidence: 99%

Nucleon axial radius and muonic hydrogen—a new analysis and review

et al. 2018

View full text Add to dashboard Cite

Weak capture in muonic hydrogen (μH) as a probe of the chiral properties and nucleon structure predictions of quantum chromodynamics (QCD) is reviewed. A recent determination of the axial-vector charge radius squared, [Formula: see text], from a model independent z expansion analysis of neutrino-nucleon scattering data is employed in conjunction with the MuCap measurement of the singlet muonic hydrogen capture rate, [Formula: see text], to update the induced pseudoscalar nucleon coupling [Formula: see text] derived from experiment, and [Formula: see text] predicted by chiral perturbation theory. Accounting for correlated errors this implies [Formula: see text], confirming theory at the 8% level. If instead, the predicted expression for [Formula: see text] is employed as input, then the capture rate alone determines [Formula: see text], or together with the independent z expansion neutrino scattering result, a weighted average [Formula: see text]. Sources of theoretical uncertainty are critically examined and potential experimental improvements are described that can reduce the capture rate error by about a factor of 3. Muonic hydrogen can thus provide a precise and independent [Formula: see text] value which may be compared with other determinations, such as ongoing lattice gauge theory calculations. The importance of an improved [Formula: see text] determination for phenomenology is illustrated by considering the impact on critical neutrino-nucleus cross sections at neutrino oscillation experiments.

show abstract

Section: Mucap Experiment: Strategy and Resultsmentioning

confidence: 99%

Nucleon axial radius and muonic hydrogen—a new analysis and review

et al. 2018

View full text Add to dashboard Cite

show abstract

“…A special isotope separation column was constructed for MuCap [9] which removed deuterium to a negligible level. A special gas circulation system [10] was constructed using thermo-dynamical cycles and cryo-absorption by Zeolite filters for continuous cleaning of the protium gas. The system reduced impurity levels to values below 20 ppb.…”

Section: The Mucap Experimentsmentioning

confidence: 99%

MuCap: Muon Capture on the Proton

Hildebrandt

Petitjean

2021

SciPost Phys. Proc.

View full text Add to dashboard Cite

The singlet muon capture rate \Lambda_SΛS on the proton \mu^-\ p \to \nu_\mu~nμ−p→νμn is determined in a high precision lifetime measurement. The main apparatus consists of a new hydrogen time projection chamber as muon detector, developed by PSI, surrounded by cylindrical wire chambers and a plastic scintillator hodoscope as electron detectors. The parameter \Lambda_SΛS is evaluated as the difference between the inverse \mu\,pμp lifetime and that of the free \mu^+μ+. The result \Lambda_S^\text{MuCap} = (715.6 \pm 5.4^\text{stat} \pm 5.1^\text{sys})\,\text{s}^{-1}ΛSMuCap=(715.6±5.4stat±5.1sys)s−1 is in excellent agreement with the prediction of chiral perturbation theory \Lambda_S^{\chi\text{PT}} = (715.4 \pm 6.9)\,\text{s}^{-1}ΛSχPT=(715.4±6.9)s−1. From \Lambda_S^\text{MuCap}ΛSMuCap a recent analysis derives for the induced pseudoscalar coupling g^\text{MuCap}_p = 8.23 \pm 0.83gpMuCap=8.23±0.83 whereas \bar{g}^{\chi\text{PT}}_p = 8.25 \pm 0.25g‾pχPT=8.25±0.25.

show abstract

“…High-Z material is used for most TPC materials, so that remaining muons stopping there are quickly captured. iii) Muon transfer to impurity elements, where capture occurs with a much higher rate than in deuterium, is suppressed by keeping the gas contamination at the 10 −9 level with a continuous circulation and filter system [21]. The purity is monitored in situ in the TPC by gas chromatography [22].…”

Section: Z X Ymentioning

confidence: 99%

MuSun - Muon Capture on the Deuteron

Kammel

2021

SciPost Phys. Proc.

View full text Add to dashboard Cite

The MuSun experiment is a precision measurement of the rate for nuclear muon capture on the deuteron, designed to resolve a long-standing disagreement between experiment and theory, and to determine an important low-energy constant relevant for a variety of weak and strong dynamics. The experiment is based on a novel active target method employing a pure deuterium cryogenic time-projection chamber. The data taking was completed in two main campaigns and the analysis is well advanced. The unique challenges and corresponding strategy of the experiment as well as the status of the analysis are presented.

show abstract

A circulating hydrogen ultra-high purification system for the MuCap experiment

Cited by 26 publications

References 5 publications

Nucleon axial radius and muonic hydrogen—a new analysis and review

Nucleon axial radius and muonic hydrogen—a new analysis and review

MuCap: Muon Capture on the Proton

MuSun - Muon Capture on the Deuteron

Contact Info

Product

Resources

About