ASTM E526-97

Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Titanium

SCOPE
1.1 This test method covers procedures for measuring reaction rates by the activation reactions  46 Ti (n, p)  46 Sc +  47 Ti (n, np)  46 Sc. Note 1-Since the cross section for the (n,np) reaction is relatively small for energies less than 12 MeV and is not easily distinguished from that of the (n,p) reaction, this test method will refer to the (n,p) reaction only.
1.2 The reaction is useful for measuring neutrons with energies above approximately 4.4 MeV and for irradiation times up to about 250 days (for longer irradiations, see Note 2).
1.3 With suitable techniques, fission-neutron fluence rates above 10  cm -2 [dot]s -1  can be determined. However, in the presence of a high thermal-neutron fluence rate,  46 Sc depletion should be investigated.
1.4 Detailed procedures for other fast-neutron detectors are referenced in Test Method E261.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Jun-1997
• Technical Committee: E10 - Nuclear Technology and Applications
• Drafting Committee: E10.05 - Nuclear Radiation Metrology

Relations

• Replaced By: ASTM E526-97(2002) - Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Titanium
• Effective Date: 10-Jun-1997

Standards Content (Sample)

STD.ASTM E52b-ENGL 1997 - 0759530 0635048 449 m
AMERICAN SOCIETY FOR TESTING AND MATERIALS
Designation: E 526 - 97
100 Barr Harbor Dr., West Conshohocken. PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Measuring Fast-Neutron Reaction Rates by Radioactivation of
Titanium’
This standard is issued under the fixed designation E 526; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (G) indicates an editorial change since the last revision or reapproval.
E 10 18 Guide for Application of ASTM Evaluated Cross
1. Scope
Section Data Files, Matrix E 706 (IIB)2
1.1 This test method covers procedures for measuring
reaction rates by the activation reactions 46Ti (n, p) 46Sc +
3. Terminology
47Ti (n, np) 46Sc.
3.1 Definitions:
NOTE I-Since the cross section for the (n,np) reaction is relatively
E 170.
3.1.1 Refer to Terminology
small for energies less than 12 MeV and is not easily distinguished from
that of the (n,p) reaction, this test method will refer to the (n,p) reaction
4. Summary of Test Method
only.
4.1 High-purity titanium is irradiated in a fast-neutron
1.2 The reaction is useful for measuring neutrons with ener-
field, thereby producing radioactive 46Sc from the 46Ti (n, p)
gies above approximately 4.4 MeV and for irradiation times 46Sc activation reaction.
up to about 250 days (for longer irradiations, see Practice 4.2 The gamma rays emitted by the radioactive decay of
E 26 1). 46Sc are counted in accordance with Methods E 18 1 and the
1.3 With suitable techniques, fission-neutron fluence rates
reaction rate, as defined by Test Method E 26 1, is calculated
above lo9 cmm2 * s-l can be determined. However, in the
from the decay rate and the irradiation conditions.
presence of a high thermal-neutron fluence rate, 46Sc deple-
4.3 The neutron fluence rate above about 4.4 MeV can
tion should be investigated.
then be calculated from the spectral-weighted neutron acti-
1.4 Detailed procedures for other fast-neutron detectors
vation cross section as defined by Test Method E 261.
are referenced in Practice E 261.
5. Significance and Use
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.1 Refer to Guide E 844 for the selection, irradiation,
responsibility of the user of this standard to establish appro-
and quality control of neutron dosimeters.
priate safety and health practices and determine the applica-
5.2 Refer to Test Method E 26 1 for a general discussion of
bility of regulatory limitations prior to use.
the determination of fast-neutron fluence rate with threshold
detectors.
5.3 Titanium has good physical strength, is easily fabri-
2. Referenced Documents
cated, has excellent corrosion resistance, has a melting
2.1 ASTM Standards:
temperature of 1675’C, and can be obtained with satisfactory
E 170 Terminology Relating to Radiation Measurements
purity.
and Dosimetry2
5.4 46Sc has a half-life of 83.81 days.3 The 46Sc decay“
E 18 1 Test Methods for Detector Calibration and Anal-
emits a 0.8893 MeV gamma 99.984 % of the time and a
ysis of Radionuclides2
second gamma with an energy of 1.1205 MeV 99.987 % of
E 261 Practice for Determining Neutron Fluence Rate,
the time.
Fluence, and Spectra by Radioactivation Techniques2
5.5 The isotopic content of natural titanium recom-
E 262 Test Method for Determining Thermal Neutron Re-
mended for 46Ti is 8.012 %.5
action and Fluence Rates by Radioactivation Techniques2
5.6 The radioactive products of the neutron reactions
E 844 Guide for Sensor Set Design and Irradiation for
47Ti(n,p)47Sc(T1/z = 3.35 d) and 48Ti(n,p)48Sc(T*/2 = 1.82 d),
Reactor Surveillance, E 706 (IIC)2
might interfere with the analysis of 46Sc.
E 944 Guide for Application of Neutron Spectrum Adjust-
5.7 Contaminant activities (for example, 65Zn and is2Ta)
ment Methods in Reactor Surveillance, (IIA)2
might interfere with the analysis of 46Sc. See Section 7.1.2
E 1005 Test Method for Application and Analysis of
and 7.1.3 for more details on the is2Ta and 65Zn interfer-
Radiometric Monitors for Reactor Vessel Surveillance,
ence.
E 706 (IIIA)2
3 Nuclear Wallet Cards, National Nuclear Data Center, prepared by Jagdish K.
Tuli, July 1990.
1 This test method is under the jurisdiction of ASTM Committee B-10 on
4 Evaluated Nuclear Structure Data Piie (ENSDP), maintained by the National
Nuclear Technology and Applications and is the direct responsibility of Subcom-
Nuclear Data Center (NNDC), Brookhaven National Laboratory, on behalf of the
mittee E10.05 on Nuclear Radiation Metrology.
Current edition approved June 10, 1997. Published May 1998. Originally International Network for Nuclear Structure Data Evaluation.
5 Isotopic Compo
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