INTEGRAL (INTErnational Gamma-Ray Astrophysics Lab)


The Coded Masks of SPI, IBIS and JEM-X instruments on board ESA Gamma Ray Mission were designed and developed at Valencia. INTEGRAL was launched in October 2002 and is still under operation phase.

INTEGRAL (International Gamma-Ray Astrophysics Laboratory) was selected by the ESA Science Programme Committee on 3 June 1993 as the next ESA medium-size scientific mission (M2) of the Horizon 2000 programme to be launched in 2002. The mission is dedicated to the fine spectroscopy (ΔE/E = 500) and fine imaging (angular resolution: 12 arcmin FWHM) of celestial gamma-ray sources in the energy range 15 keV to 10 MeV with concurrent source monitoring in the X-ray (3-35 keV) and optical (V-band, 550 nm) energy ranges.

INTEGRAL satellite is the largest Gamma-Ray Astrophysics mission foreseen for this decade. Since its selection in 1994, three very innovative technologies were identified to achieve the INTEGRAL scientific goals: new generation Solid State Detectors, Active Veto Systems and Spatial Signal Multiplexing Systems.

The Integral payload consists of two main gamma-ray instruments, the Spectrometer SPI and the Imager IBIS. Each of them has both spectral and angular resolution, but they are differently optimised in order to complement each other and to achieve overall excellent performance. These instruments are supported by two monitor instruments which will provide complementary observations at X-ray and optical energy bands: the X-Ray Monitor JEM-X and the Optical Monitoring Camera OMC. The Spectrometer, Imager and JEM-X share a common principle of operation: they are all Coded Mask telescopes. The coded-mask technique is the key which allows imaging, which is all-important in separating and locating sources.

The Grupo de Astronomía y Ciencias del Espacio (GACE) of the University of Valencia was chosen as the responsible to design and develop the Spatial Signal Multiplexing Systems (Coded Masks) for the three instruments, appointing the Spanish company SENER as the Prime Industrial Contractor.