Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences01:17

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

818
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
818
Atomic Nuclei: Nuclear Spin State Population Distribution01:14

Atomic Nuclei: Nuclear Spin State Population Distribution

993
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
993
Atomic Nuclei: Magnetic Resonance01:05

Atomic Nuclei: Magnetic Resonance

667
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
667
Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

661
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis.
661
Nuclear Stability03:18

Nuclear Stability

18.9K
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together...
18.9K
Atomic Nuclei: Nuclear Spin State Overview01:03

Atomic Nuclei: Nuclear Spin State Overview

978
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
978

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Out-of-field neutron radiation from clinical proton, helium, carbon, and oxygen ion beams.

Medical physics·2025
Same author

Calibration of the W-PIE neutron spectrometer at CERF reference facility.

Radiation protection dosimetry·2023
Same author

EURADOS project on the impact of the proposed ICRU operational dose quantities.

Radiation protection dosimetry·2023
Same author

EURADOS REM-COUNTER INTERCOMPARISON AT MAASTRO PROTON THERAPY CENTRE: COMPARISON WITH LITERATURE DATA.

Radiation protection dosimetry·2022
Same author

Joint EURADOS WG9-WG11 rem-counter intercomparison in a Mevion S250i proton therapy facility with Hyperscan pulsed synchrocyclotron.

Physics in medicine and biology·2022
Same author

Impact of new operational dosimetric quantities on individual monitoring services.

Journal of radiological protection : official journal of the Society for Radiological Protection·2021

Related Experiment Video

Updated: Jul 13, 2025

High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water
08:48

High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water

Published on: April 28, 2022

1.8K

Measurements in pulsed neutron fields.

Marco Caresana1, Andrea Cirillo1, Matteo Bolzonella1

  • 1Politecnico di Milano- Dipartimento di Energia, Via Labmruschini 4, Milano 20156, Italy.

Radiation Protection Dosimetry
|October 11, 2023
PubMed
Summary

Measuring radiation in pulsed fields is difficult for standard detectors. This review highlights European efforts to address challenges in pulsed and mixed radiation dosimetry, identifying remaining issues and training needs.

More Related Videos

Measurements of Soil Carbon by Neutron-Gamma Analysis in Static and Scanning Modes
07:51

Measurements of Soil Carbon by Neutron-Gamma Analysis in Static and Scanning Modes

Published on: August 24, 2017

7.4K
Neutron Crystallography Data Collection and Processing for Modelling Hydrogen Atoms in Protein Structures
10:10

Neutron Crystallography Data Collection and Processing for Modelling Hydrogen Atoms in Protein Structures

Published on: December 1, 2020

5.0K

Related Experiment Videos

Last Updated: Jul 13, 2025

High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water
08:48

High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water

Published on: April 28, 2022

1.8K
Measurements of Soil Carbon by Neutron-Gamma Analysis in Static and Scanning Modes
07:51

Measurements of Soil Carbon by Neutron-Gamma Analysis in Static and Scanning Modes

Published on: August 24, 2017

7.4K
Neutron Crystallography Data Collection and Processing for Modelling Hydrogen Atoms in Protein Structures
10:10

Neutron Crystallography Data Collection and Processing for Modelling Hydrogen Atoms in Protein Structures

Published on: December 1, 2020

5.0K

Area of Science:

  • Radiation Detection and Measurement
  • Applied Physics
  • Nuclear Engineering

Background:

  • Pulsed and mixed radiation fields pose significant challenges for accurate dosimetry.
  • Standard active neutron detectors (e.g., REM-counters, Bonner sphere spectrometers) are often inadequate due to dead time losses in pulsed fields.
  • Stray radiation fields around accelerators maintain the primary beam's pulsed structure, complicating workplace monitoring.

Purpose of the Study:

  • To review efforts by the European Radiation Dosimetry Group (EURADOS) Working Group 11 to address dosimetry in pulsed and mixed radiation fields.
  • To define the problem, characterize existing instrumentation, and propose solutions for monitoring these fields.
  • To identify remaining challenges and areas for improvement in pulsed radiation dosimetry.

Main Methods:

  • Literature review of EURADOS Working Group 11 activities and publications.
  • Analysis of instrumentation limitations in pulsed radiation environments.
  • Identification of metrological and characterization gaps.

Main Results:

  • EURADOS has made efforts to define and characterize instrumentation for pulsed and mixed radiation fields.
  • Existing active neutron detectors show limitations in accurately measuring pulsed fields.
  • Several open issues persist, including the lack of metrological traceability for pulsed neutron fields.

Conclusions:

  • Accurate dosimetry in pulsed and mixed radiation fields remains a significant challenge.
  • Further optimization and characterization of available instruments are needed.
  • Education and training initiatives are crucial to address the identified gaps in expertise and practice.