Review comment:
Non-threshold reactions measured in fast spectra such as the 252Cf(sf) and 235U(nth,f) spectrum tend to have their spectrum averaged cross section dominated by scattering contributions and ‘room-return’ neutrons. Experiments should be designed to minimize these contributions and maximize the reaction rate from the primary source. For new experiments best estimates must be provided by detailed Monte Carlo calculation of the spectrum realized in the experiment and the Monte Carlo model must be made available to IRDFF to facilitate validation of new proposals for the cross section. In all cases it is advised to publish both the fully corrected SACS and the measured reaction rates of the primary reaction and the monitor reactions used for normalization and validation of the model. The measured reaction rates must be provided with a full covariance matrix.

Entry Status:
Work in progress (as of SG-C review of May 2018)

Main references:
Please report any missing information to hprlinfo@oecd-nea.org

Theory/Evaluation

Additional file attached:Simakov2017.pdf
Additional file attached:SPA_CE_U235.pdf

Request ID	89		Type of the request	Special Purpose Quantity
Target	Reaction and process	Incident Energy	Secondary energy or angle	Target uncertainty	Covariance
29-CU-63	(n,2n) SIG	20 MeV-100 MeV		5-10	Y
Field	Subfield	Date Request created	Date Request accepted	Ongoing action
Dosimetry	High-energy	06-OCT-17	06-OCT-17

Requester: Dr Stanislav SIMAKOV at KIT, GER
Email: intersurfen@gmail.com

Project (context): IRDFF project

Impact:
The International Reactor Dosimetry and Fusion File (IRDFF) aims at providing evaluated neutron dosimetry reactions validated for all applications related to fission reactors and fusion technology development [IAEA2017].

Accuracy:
5%-10%

Justification document:
Accurate cross sections as well as spectrum-averaged cross sections (SACS) in relevant and well-characterized neutron fields are essential for improvement and validation of the evaluated data [Simakov2017].

Comment from requester:
The IRDFF project strives to evaluate, and eventually add to the library, high-threshold reactions with cross section plateaus located between 15/20 MeV and 100/150 MeV to meet the requirements of the accelerator-driven high-energy neutron sources. Note that it is important to know the cross section tail up to 100/150 MeV in order to allow the deconvolution of high-energy quasi-monoenergetic neutron source spectra.

References