Secondary photon fields produced in accelerator-based sources for neutron generation.

Radiat Prot Dosimetry

Dipartimento di Ingegneria Nucleare, Politecnico di Milano, via Ponzio 34/3, 20133 Milano, Italy.

Published: March 2006

Neutrons can be produced with low-energy ion accelerators for many applications, such as the characterisation of neutron detectors, the irradiation of biological samples and the study of the radiation damage in electronic devices. Moreover, accelerator-based neutron sources are under development for boron neutron capture therapy (BNCT). Thin targets are used for generating monoenergetic neutrons, while thick targets are usually employed for producing more intense neutron fields. The associated photon field produced by the target nuclei may have a strong influence on the application under study. For instance, these photons can play a fundamental role in the design of an accelerator-based neutron source for BNCT. This work focuses on the measurement of the photon field associated with neutrons that are produced by 4.0-6.8 MeV protons striking both a thin 7LiF target (for generating monoenergetic neutrons) and a thick beryllium target. In both cases, very intense photon fields are generated with energy distribution extending up to several MeV.

Download full-text PDF

Source
http://dx.doi.org/10.1093/rpd/nci146DOI Listing

Publication Analysis

Top Keywords

photon fields
8
neutrons produced
8
accelerator-based neutron
8
generating monoenergetic
8
monoenergetic neutrons
8
neutrons thick
8
photon field
8
neutron
6
secondary photon
4
produced
4

Similar Publications

Magnetophononics and the chiral phonon misnomer.

PNAS Nexus

January 2025

The Harrison M. Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI 48109-1040, USA.

The direct, ultrafast excitation of polar phonons with electromagnetic radiation is a potent strategy for controlling the properties of a wide range of materials, particularly in the context of influencing their magnetic behavior. Here, we show that, contrary to common perception, the origin of phonon-induced magnetic activity does not stem from the Maxwellian fields resulting from the motion of the ions themselves or the effect their motion exerts on the electron subsystem. Through the mechanism of electron-phonon coupling, a coherent state of circularly polarized phonons generates substantial non-Maxwellian fields that disrupt time-reversal symmetry, effectively emulating the behavior of authentic magnetic fields.

View Article and Find Full Text PDF

Wearable optical coherence tomography angiography probe with extended depth of field.

J Biomed Opt

January 2025

Tsinghua University, State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Beijing, China.

Significance: Optical coherence tomography (OCT) is widely utilized to investigate brain activities and disorders in anesthetized or restrained rodents. However, anesthesia can alter several physiological parameters, leading to findings that might not fully represent the true physiological state. To advance the understanding of brain function in awake and freely moving animals, the development of wearable OCT probes is crucial.

View Article and Find Full Text PDF

[Vacuum ultraviolet laser dissociation and proteomic analysis of halogenated peptides].

Se Pu

February 2025

CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.

Chemical modifications are widely used in research fields such as quantitative proteomics and interaction analyses. Chemical-modification targets can be roughly divided into four categories, including those that integrate isotope labels for quantification purposes, probe the structures of proteins through covalent labeling or cross-linking, incorporate labels to improve the ionization or dissociation of characteristic peptides in complex mixtures, and affinity-enrich various poorly abundant protein translational modifications (PTMs). A chemical modification reaction needs to be simple and efficient for use in proteomics analysis, and should be performed without any complicated process for preparing the labeling reagent.

View Article and Find Full Text PDF

Cellulose-based photo-curable chiral nematic ink for direct-ink-writing 3D printing.

Carbohydr Polym

March 2025

Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China. Electronic address:

3D printing technology is one of the most promising strategies for constructing topological functional materials. The development of functional inks is a core issue in the technical development of 3D printing technology. In this study, we engineered photonic crystal inks based on chiral nematic liquid crystals of cellulose derivative, i.

View Article and Find Full Text PDF

Bipolar Solid-Solution Hosts for Efficient Crystalline Organic Light-Emitting Diodes.

ACS Appl Mater Interfaces

January 2025

State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.

Crystalline organic semiconductors, recognized for their highly ordered structures and high carrier mobility, have emerged as a focal point in the field of high-performance optoelectronic devices. Nevertheless, the intrinsic unipolar properties, characterized by imbalanced hole and electron transport capabilities, have continuously represented a significant challenge in the advancement of high-performance crystalline thin-film organic light-emitting diodes (C-OLEDs). Here, a bipolar solid-solution thin film with a maintained crystal structure has been fabricated using 2-(4-(9H-carbazol-9-yl)phenyl)-1(3,5-difluorophenyl)-1H-phenanthro [9,10-d]imidazole (2FPPICz) and 4-(1-(3,5-difluorophenyl)-1H-imidazo[4,5-][1,10]phenanthrolin-2-yl)-N,N-diphenylaniline (2Fn) via a weak epitaxial growth (WEG) process, exhibiting nearly equivalent hole and electron mobilities (10-10 cm V s).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!