A NEUTRON IRRADIATION DEVICE FOR THE TESTING OF MICROELECTRONIC COMPONENETS TO BE USED IN THE RADIATION ENVIRONMENT OF HIGH-ENERGY PARTICLE ACCELERATORS AT DESY B. Mukherjee 1 , D. Makowski 2 , A. Kalicki 3 , D. Rybka 3 , M. Grecki 2 , S. Simrock 1
A NEUTRON IRRADIATION DEVICE FOR THE TESTING OF MICROELECTRONIC COMPONENETS TO BE USED IN THE RADIATION ENVIRONMENT OF HIGH-ENERGY
PARTICLE ACCELERATORS AT DESY
B. Mukherjee1, D. Makowski2, A. Kalicki3, D. Rybka3,
M. Grecki2 , S. Simrock1
1Deutsches Elektronen Synchrotron, Hamburg, Germany
2Department of Microelectronics and Computer Science, TUL, Poland
3Institute of Electronic Systems, WUT, Poland
12th International MIXDES Conference, 22-25 June 2005, Krakow, Poland
A significant number of microelectronic instrumentation and control devices vital to the operation of the VUV-Free Electron Laser (FEL) of DESY will be located in the close vicinity of the 1.2 GeV super-conducting electron linac driving the FEL.
During the linac operation the microelectronic components will be subjected to parasitic radiation field, primarily made of brems-strahlung and photoneutrons.
The radiation exposure will trigger Soft-Error (Single Event Upset) as well as Permanent Damage in the electronic circuitry.
We have developed a variable energy neutron irradiation device for the radiation effect testing of microelectronic components.
The device is based on a 241Am-Be(a, n) source placed at the centre of a water filled jar acting as neutron moderator. The neutron energy variation is accomplished by varying the jar diameter.
B: Thermal Neutron Shield (Borated Polyethylene)
D: Device under Test (DUT)
J1, J2: Jars (16 and 33 cm radius respectively)
S: 241Am-Be Neutron source
T: Tripod (Source holder)
Photograph of the neutron
Irradiation device showing diverse types of DUT
The Reference Neutron Spectra
(a) Un-moderated, En (av) = 5.2 MeV
(b) Moderated (6.9 cm H2O), En (av) = 4.1 MeV
(c) Moderated (15.9 cm H2O), En (av) = 3.2 MeV
The areas under the histogram (a), (b) and (c)
are normalised to unity.
Tmod = Moderator (H2O) Thickness
SDD = Source to Detector Distance
Hnm = Measured Neutron Dose Equiv.
Hnc = Calculated Neutron Dose Equiv
Hgm = Measured Gamma Dose Equiv.
* With thermal neutron shield
The Neutron Dose Equivalent at various moderator thicknesses was verified by Superheated Bubble Dosimeters (Gamma Insensitive)
The background Gamma Dose at various moderator thicknesses was verified by a PIN Diode based miniature Electronic Dosimeter
We have irradiated the following items
(1) Commercially available SRAM chips of 256, 512, 1024 and 2048 kB
memory density (s. Table below)
(2) Two miniature CCD Cameras
(1) Un-moderated neutrons
(2) Neutrons moderated with 6.9 cm H2O layer
(3) Moderated neutrons (as above),Shielded (3.5 mm Bor-Poly) Irradiation device
Specifications of the SRAM (Static Random Access Memory) Chips used in this Investigation.
Neutron induced SEU in CCD Cameras for two exposure modes.
Number of SEU in 512 kB SRAM Chips induced by neutrons for three exposure modes.
Results showing the neutron irradiation effects in SRAM chips of four different
We have demonstrated the construction and operation principles of a simple variable energy neutron irradiation device based on an isotopic neutron source.
The system consists of a 241Am-Be (a, n) source located at the centre of an assembly of concentric polyethylene jars of 8.0 and 16.5 cm radius respectively.
The primary neutrons from the 241Am-Be (a, n) source with an energy of 5.2 MeV was moderated with 6.9 (Jar 1) and 15 (Jar 2) cm thick water layers to obtain the neutron radiation field of 4.1 and 3.2 MeV average energy respectively.
The neutron dose equivalents at different configurations (Moderator layer thickness) and the corresponding gamma background doses were estimated with Superheated bubble dosimeter and PIN diode dosimeter respectively.
A cylindrical thermal neutron shield made of 3.5 mm thick borated polyethylene sheet was used to attenuate the thermal neutron component of the irradiation field.
A radiation hardness of various microelectronic devices like, SRAM and FPGA chips as well as CCD cameras have been tested using the above device prior to their installation in the high-energy accelerator environment at DESY.
THANK YOU FOR YOUR ATTENTION