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.

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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
alpha particle [MeV]
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)