scholarly journals Precise Neutron Lifetime Experiment Using Pulsed Neutron Beams At J-PARC

2017 ◽  
Author(s):  
Naoki NAGAKURA ◽  
Katsuya Hirota ◽  
Sei Ieki ◽  
Takashi Ino ◽  
Yoshihisa Iwashita ◽  
...  
Keyword(s):  
Neutron Lifetime ◽  
Neutron Beams ◽  
Pulsed Neutron

Using Pulsed Cold Neutrons to Measure Neutron Lifetime

2021 ◽  
Vol 1 ◽  
Keyword(s):  
Neutron Lifetime ◽  
Cold Neutrons ◽  
Neutron Beams ◽  
Pulsed Neutron

Scientists measure the lifetime of a neutron with pulsed neutron beams to explore the cause of a puzzling discrepancy in their previously measured lifetime.

scholarly journals Precise Neutron Lifetime Measurement Using Pulsed Neutron Beams at J-PARC

2021 ◽  
Author(s):  
N. Sumi ◽  
K. Hirota ◽  
G. Ichikawa ◽  
T. Ino ◽  
Y. Iwashita ◽  
...  
Keyword(s):  
Lifetime Measurement ◽  
Neutron Lifetime ◽  
Neutron Beams ◽  
Pulsed Neutron

A diffusion model for pulsed neutron logging

Geophysics ◽  
1989 ◽  
Vol 54 (1) ◽  
pp. 100-113 ◽  
Author(s):  
Keh‐Jim Dunn
Keyword(s):  
Thermal Neutron ◽  
Gamma Ray ◽  
Decay Curve ◽  
Complete Solution ◽  
Theoretical Solution ◽  
Neutron Lifetime ◽  
Weak Absorption ◽  
Unrealistic Assumption ◽  
Pulsed Neutron ◽  
Borehole Size

Based on Polyachenko’s formulation, the complete solution of the boundary value problem for pulsed neutron logging is derived for a centralized tool model. The solution is more general than Polyachenko et al.’s earlier solution in that the unrealistic assumption of zero thermal neutron lifetime in the fluid‐filled borehole is eliminated and that, in addition to the formation signal, the borehole signal is also considered. For formations of weak absorption, the theoretical solution predicts features in the gamma‐ray die‐away curve similar to those observed in real logging cases. For formations of strong absorption, the asymptotic behavior of the gamma‐ray decay curve is influenced by the borehole size. This theoretical solution, even though not directly applicable to the complex real logging environment, offers us a means for understanding qualitatively the interrelationship among all thermal neutron parameters of the borehole and the formation.

scholarly journals Concentration of the velocity distribution of pulsed neutron beams

2017 ◽  
Vol 2017 (4) ◽  
Author(s):  
Masaaki Kitaguchi ◽  
Yoshihisa Iwashita ◽  
Hirohiko M. Shimizu
Keyword(s):  
Velocity Distribution ◽  
Neutron Beams ◽  
Pulsed Neutron

scholarly journals Neutron lifetime measurement with pulsed cold neutrons

2020 ◽  
Author(s):  
K Hirota ◽  
G Ichikawa ◽  
S Ieki ◽  
T Ino ◽  
Y Iwashita ◽  
...  
Keyword(s):  
Decay Rate ◽  
Reaction Rate ◽  
Proton Accelerator ◽  
Neutron Decay ◽  
Spallation Neutron Source ◽  
Neutron Lifetime ◽  
Cold Neutrons ◽  
Research Complex ◽  
Gas Chamber ◽  
Pulsed Neutron

Abstract The neutron lifetime has been measured by comparing the decay rate with the reaction rate of 3He nuclei of a pulsed neutron beam from the spallation neutron source at the Japan Proton Accelerator Research Complex (J-PARC). The decay rate and the reaction rate were determined by simultaneously detecting electrons from the neutron decay and protons from the 3He(n, p) 3H reaction using a gas chamber of which working gas contains diluted 3He. The measured neutron lifetime was 898 ± 10stat+15−18sys s.

scholarly journals Laser-driven neutrons for time-of-flight experiments?

2020 ◽  
Vol 239 ◽  
pp. 17012
Author(s):  
M.A. Millán-Callado ◽  
C. Guerrero ◽  
J.M. Quesada ◽  
J. Gómez ◽  
B. Fernández ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Production Method ◽  
Power Laser ◽  
Vast Number ◽  
Detection Techniques ◽  
Neutron Beams ◽  
Research Fields ◽  
New Applications ◽  
Physics Experiments ◽  
Pulsed Neutron

Neutron beams, both pulsed and continuous, are a powerful tool in a wide variety of research fields and applications. Nowadays, pulsed neutron beams are produced in conventional accelerator facilities in which the time-of-fight technique is used to determine the kinetic energy of the neutrons inducing the reactions of interest. In the last decades, the development of ultra-short (femtosecond) and ultra-high power (> 1018 W/cm2) lasers has opened the door to a vast number of new applications, including the production and acceleration of pulsed ion beams. These have been recently used to produce pulsed neutron beams, reaching fluxes per pulse similar and even higher than those of conventional neutron beams, hence becoming an alternative for the pulsed neutron beam users community. Nevertheless, these laser-driven neutrons have not been exploited in nuclear physics experiments so far. Our main goal is to produce and characterize laser-driven neutrons but optimizing the analysis, diagnostic and detection techniques currently used in conventional neutron sources to implement them in this new environment. As a result, we would lay down the viability of carrying out nuclear physics experiments using this kind of sources by identifying the advantages and limitations of this production method. To achieve this purpose, we plan to perform experiments in both medium (50TW@L2A2, in Santiago de Com-postela) and high (1PW@APOLLON, in Paris) power laser facilities.

Highly flexible PC-based data acquisition system for TOF measurements with pulsed neutron beams

1995 ◽  
Vol 42 (6) ◽  
pp. 2317-2321 ◽  
Author(s):  
K.D. Muller ◽  
B. Alefeld ◽  
J. Lerch ◽  
R. Reinartz ◽  
P. Reinhart ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Neutron Beams ◽  
Pulsed Neutron

Loss-free polarization of pulsed neutron beams

2002 ◽  
Vol 74 (0) ◽  
pp. s231-s233 ◽  
Author(s):  
S. M�ller ◽  
G. Badurek
Keyword(s):  
Neutron Beams ◽  
Pulsed Neutron ◽  
Free Polarization
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