Gamma radiation from a Co-60 source is a standard method for simulating the deposition of “ionizing” energy due to the charged particles of the space environment. The cumulated dose can induce a degradation of electrical and functional parameters up to the destruction of the electronic components.
TRAD is a European leader in total dose testing. Our new irradiation facility will allow us to improve cost and reactivity, and to ensure a high quality service providing irradiation procedures compliant with MIL-STD, ESA/SCC, ASTM or other specifications.
I. FACILITY CHARACTERISTICS
With a panoramic Cobalt-60 source of 7.4 TBq, the useful irradiation volume is @45 m3. The facility offers a gamma ray beam dose rate from 1 krad(Si)/h to 7 rad(Si)/h (0.3 rad(Si)/s to 2 mrad(Si)/s). Possibility to irradiate under 7 rad(Si)/h with a lead wall.
The chamber temperature is 20°C (±2%). A large irradiation volume with a uniform dose rate distribution allows the testing of complete systems. The operation of the irradiator is fully automatic and is controlled by an electronic control unit.
Reliable dosimetry: Dose rate measurement, its spatial distribution within the test volume and the energy spectrum are provided for complete analysis of the degradation mechanisms.
We supply a precise dosimetry at the components location. In addition, a dosimeter is placed on the irradiated board to control total deposited dose. In future work, we have scheduled a collaborative effort between TRAD and ESA to perform "Inter-laboratory" dosimetry measurements.
We will perform simulations in order to demonstrate that low-energy scattered radiation does not cause dosimetry errors due to dose enhancement. The energy contribution is evaluated for dose deposition at different positions as described in Figure at right. More than 95% of dose is due to high energy. Contribution of low energies is negligible.
III. TECHNICAL CONDITIONS
The access team is composed of 4 authorized personnel, allowing permanent access availability combined with optimized security. A manager in charge of radioprotection & organization and 3 operators trained to operate the irradiator and give access to the irradiation chamber.
Both passive and active dosimeters are compulsory to reach the irradiation chamber. Active dosimeters are available for external industrial users.
The well-known temperature dependence of radiation effects requires active temperature control to ensure repeatability of the irradiation conditions. An accurate system for component positioning in the beam, associated with frequent dosimetry measurements, ensures a reliable measurement of deposited dose at component level.
On-line monitoring of the degradation phenomena is essential and can be included at all times thanks to cable passages distributed along the wall, allowing in-line communication between the irradiation chamber and the test bench located in the adjacent room. Some cable passages reduce the cable lengths to less than 4m.
IV. ON-SIGHT SECURITY
Security is a major concern at TRAD. All accesses to the GAMRAY are strictly controlled, as specified above. Our Prevention Plan strictly complies with French law on Health and Safety rules and regulations. Furthermore, we place great importance in regular enhanced Radiation Protection training for all those who intervene on the site, be it TRAD employees or visiting customers. In this way, we are able to monitor everyone involved for maximum safety.
V. CUSTOMER FACILITIES
A dedicated test room is available for customers, with independent cable passages. The customer test room has internet access and an independent telephone line. The customer can use his own equipment or we can make available extra tools and equipment, if necessary.
Standard access to the GAMRAY is from 9-11am and 14-16pm. It will be possible to extend these hours for customers in very specific cases.
Access to the GAMRAY is reserved to ionizing radiation authorized personnel - Category B. This personnel shall be accompanied by a dedicated TRAD staff member. We can also provide authorized personnel should the customer not have his own.
Our ISO 9001 V2008 certification was extended to the Co60 facility in October 2012.