Further Observations of Cosmic-Ray Events in Nuclear Emulsions Exposed Below Ground

George, E. P.; Evans, John

doi:10.1088/0370-1298/68/9/308

Cited by 19 publications

(7 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14 (j~ stopped/kg min obtained by Takagi and Tanaka. If a 50% error is assigned to the extrapolation from 60 mwe to 2 mwe in depth, our value is consistent with that of Bergamasco et al [1970] but not with those of Barton and Slade [1965], Short [1963], George and Evans [1955], and Kaneka et al [1955]. According to Short's calculation, the stopping rate at 60-mwe depth underground is 1/28 of the 37 stopping rate at sea level.…”

supporting

confidence: 61%

“…His stopping rate is 2. 5 times higher than that obtained by George and Evans [1955] at 58-mwe depth with glass-backed nuclear emulsions. From his best estimate of the momentum spectrum of muons at sea level, Short [1963] also calculated the expected stopping rates at depths underground of 7-70 mwe.…”

mentioning

confidence: 57%

“…His stopping-ratedepth curve, which was normalized to his measured rate at 58-mwe depth, is also a factor of 2. 5 higher than the rates observed by George and Evans [1955] and by Kaneka et al [1955] at depths shallower than 58 mwe. Short's stopping-rate-depth curve gives 0.…”

mentioning

confidence: 61%

“…Takagi and Tanaka [1969] calculated that the number of muons stopped at 2 mwe and that at 7 mwe are practically identical. Because of the uncertainties in the calculated extrapolation to 2-mwe depth, we give Short's rate to be 0.2 [i /kg min stopped at 2 mwe and the rates of George and Evans [1955] and Kaneka et al [1955] to be 0.1 \T/kg min at 2 mwe with a 50% error in Table 3. With a liquid scintillator, Bergamasco et al [1970] measured the stopping rate of muons at depths underground of 60-300 mwe. At 60-mwe depth, the stopping rate of Bergamasco et al [1970] is a factor of 2 higher than that of Short [1963]; a factor of 5 higher than that of George and Evans [1955] ; and a factor of 2 higher than that of Barton and Slade [1965], which was also obtained with a liquid scintillator.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Stopping rate of negative cosmic-ray muons near sea level

Spannagel¹,

Fireman²

1972

J. Geophys. Res.

View full text Add to dashboard Cite

A production rate of 0. 065 ± 0. 003 Ar atom/kg min of K at 2-mwe depth below sea level was measured by sweeping argon from potassium solutions. This rate is unaffected by surrounding the solution by paraffin and is attributed to negative-muon captures and the electromagnetic interaction of fast muons, and not to a nucleonic cosmic-ray component. The 37 39 Ar yield from K by the stopping of negative muons in a muon beam of the SREL synchrocyclotron was measured to be 8. 5 ± 1. 7%. The stopping rate of negative cosmic-ray muons at 2-mwe depth below sea level from these measurements and an estimated 17% electromagnetic production is 0.63 ± 0.13 |_i /kg min. Previous measurements on the muon stopping rate vary by a factor of 5. Our value is slightly higher but is consistent with two 37 previous high values. The sensitivity of the Ar radiochemical method for the detection of muons is considerably higher than that of the previous radiochemical methods and could be used to measure the negative-muon capture rates at greater depths. IntroductionUntil the experiments of the Utah cosmic-ray group [Bergeson et al., 1967], it was universally believed that cosmic-ray muons result solely from the decay of secondary pions and kaons from cosmic-ray interactions in the atmosphere. The Utah experiment raised the possibility for an additional source of muons. An explanation [Bjorken et al., 1969] of the Utah experiment has been proposed that requires an anomalous absorption of muons of negative helicity and unusual shape for the sea-level muon energy spectrum. This spectrum is often inferred from stopping rate versus depth measurements near sea level. Although the muon stopping rate has been 111-098 measured by three different methods, measurements by even the same method often disagree. Stopped muon rates have mainly been measured with nuclear emulsions and with scintillators at depths to 300 mwe (meters of water equivalent). Recent measurements by Bergamasco [1970] are a factor of 2-5 higher than previous ones. Additional measurements of the stopped negative-muon rate might be helpful in determining whether cosmic muons result solely from the decay of secondary IT and K mesons.Until now, because of restricted sensitivity, radiochemical methods for detection have yielded positive results to a depth of only 0.2 mwe. Winsberg [1956] Cl from rainwater produced by the Ar (|jt , v n) reaction. Rama and Honda [1961] extracted gold radioactivities from mercury at sea level and state that their result is 59 consistent with Winsberg's. Takagi and Tanaka [1969] observed a Fe radioactivity of 0. 35 ± 0.14 atom/kg min induced by cosmic-ray muons in cobalt at sea level. This is a lower limit for the stopping of negative muons because the yield of the reaction was not determined. A more sensitive radiochemical method with a measured yield is needed. -37The K ([i , v 2n)Ar reaction offers the possibility for extremely high sensitivity because it is possible to extract argon with almost 100% efficiency from large 37 volumes of potassium ...

show abstract

supporting

confidence: 61%

mentioning

confidence: 57%

mentioning

confidence: 61%

mentioning

confidence: 99%

See 2 more Smart Citations

Stopping rate of negative cosmic-ray muons near sea level

Spannagel¹,

Fireman²

1972

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…5, 6 Inelastic muon interactions were first studied using nuclear emulsions and underground cosmic rays. 7 It became possible to produce muon beams with small contamination using accelerators and nuclear emulsion experiments have measured inelastic cross sections for the energies available. [8][9][10] …”

Section: Acknowledgmentsmentioning

confidence: 99%