Alpha Spectroscopy Sources
The products shown on these pages are representative sources used for common applications.
If you cannot find the product with your specifications, please contact us using the corresponding email contact on this website. In most cases we will be able provide you with a solution meeting your requirements.
You can also use our product request forms.
Applications
Alpha spectrometry sources are intended for calibrating and checking solid state alpha spectrometers, for applications in environmental monitoring and research.
The advantages of these sources are:
- Narrow line widths (normally less than 20keV) - easy, accurate, calibration of spectrometer
- Wipe test results comparable to sealed sources - low risk of contaminating equipment
Construction
The radionuclides are deposited onto a stainless steel disc, 25mm in diameter, 0.5mm thick (drawing: VZ-1679-001).The reagents used are ultra-pure, resulting in an essentially mass less deposit. This process minimizes line broadening and produces sources exhibiting line widths of less than 20keV full width half maximum (sources containing Np-237 have line widths typically 50keV, due to the low specific activity of Np-237). Wipe test results comparable with sealed sources are achieved for this manufacturing process. However, any material placed over the active deposit will degrade the spectrum, so it is not possible to construct a source that can be classified as a sealed source as defined in ISO2919.
Certification
Calibrated single nuclide sources are supplied with a DAkkS certificate stating alpha particle emission rate and activity. Triple nuclide sources are designed for energy calibration applications.
Uncertainties
The reported uncertainty is based on a standard uncertainty multiplied by a coverage factor k=2, providing a level of confidence of approximately 95%. The expanded uncertainty of the emission rate for a calibrated single nuclide source is =3 %.
Traceability
The sources are traceable to standards held by national laboratories such as the Physikalisch-Technische Bundesanstalt (PTB, Germany), the National Physical Laboratory (NPL, UK), the National Institute of Standards and Technology (NIST, USA) the Laboratoire Primaire des Rayonnements Ionisants ( France), and many other national laboratories world-wide. Further details are given in the section General Technical Information.
Recommendations on source handling
To maintain the accuracy of measurements, these sources must be handled with care. Sources should be handled with tweezers to avoid leaving grease on the surface of the source, which would degrade the spectrum. The sources must not be cleaned with abrasive compounds such as metal polish, as this would remove the active deposit. The sources should be kept in their storage boxes when not in use.
Tolerances
The maximum deviation of the measured activity at the reference time from the nominal value is +/-30%.
Availability
The sources are normally delivered within 4-6 weeks from receipt of order.
Quality assurance
The sources are calibrated at Eckert & Ziegler Nuclitec GmbH’s DAkkS accredited measurement laboratory in Germany. The manufacturing facility operates a quality management system which has been independently audited and approved to ISO9001:2008.
Radionuclide | Alpha particle energy [MeV] | Intensity [%] |
Np-237 | 4.640 | 6.2 |
| 4.766 | 8.0 |
| 4.772 | 25.0 |
| 4.788 | 47.0 |
Pu-239 | 5.105 | 11.5 |
| 5.143 | 15.1 |
| 5.155 | 73.4 |
Am-241 | 5.388 | 1.4 |
| 5.443 | 12.8 |
| 5.486 | 85.2 |
Pu-238 | 5.456 | 28.3 |
| 5.499 | 71.6 |
Cm-244 | 5.763 | 23.3 |
| 5.805 | 76.7 |
To help select the source needed, the energies and intensities of the most intense alpha particles emitted by the different nuclides are shown in the table.
Ordering Information
Radionuclide | Nominal activity | Energy of most intense | Product code uncalibrated1) | Product code calibrated2) |
Am-241 | 50 Bq | 5.486 | AMR11 | AMR21 |
| 500 Bq | 5.486 | AMR12 | AMR22 |
| 5000 Bq | 5.486 | AMR13 | AMR23 |
| 40000 Bq | 5.486 | AMR14 | n/a |
Pu-238 | 1000 Bq | 5.499 | PPRB2505 | PPRB2497 |
Pu-239 | 1000 Bq | 5.155 | PIRB2506 | PIRB2498 |
Cm-244 | 1000 Bq | 5.805 | CLRB2507 | CLRB2499 |
mixed nuclide:
| QCRB2508 | QCRB25003) | ||
Pu-239 Am-241 Cm-244
| 1000 Bq 1000 Bq 1000 Bq
| 5.155 5.486 5.805
|
|
|
| ||||
| ||||
mixed nuclide:
| QCRB4020 | QCRB40213) | ||
Np-237 Am-241 Cm-244
| 150 Bq 100 Bq 100 Bq
| 4.788 5.486 5.805
|
|
|
1) For energy calibration only - no certificate of calibration is included
2) For energy and efficiency calibration - DAkkS certificate of calibration included
3) The certificate of calibration states the total a emission rate and the nominal activities of individual radionuclides. EZN certificate only.
Composite alpha source
The composite alpha source is designed to be used as an energy marker for alpha spectroscopy systems. Pu-239, Am-241 and Cm-244, 370 Bq each, are electroplated onto a polished platinum or platinum clad nickel foil. The active area is 0.197” (5.0 mm). The source is supplied uncovered. These nuclides provide alpha particles from approximately 5100 to 5800 keV and exhibit line widths typically less than 20 keV FWHM. This energy range is wide enough to provide a valid energy calibration for most alpha emitting nuclides.
The source, when purchased as a NIST traceable standard, can also be used to determine detector efficiencies for alpha particles. Total activity and individual activities are provided on the Certificate of Calibration.
The composite alpha source is available in the type A-2, A-1 and PM configurations.
option: window material: 100µg/cm2 gold
(15 keV FWHM increase, 15 keV energy decrease)
