A Low Complexity Detector with MRC Diversity Reception for MCIK-OFDM

Multi-carrier index keying (MCIK) is a recently developed transmission technique that exploits the sub-carrier indices as an additional degree of freedom for data transmission. This paper investigates the performance of a low complexity detection scheme with diversity reception for MCIK with orthogonal frequency division multiplexing (OFDM). For the performance evaluation, an exact and an approximate closed form expression for the pairwise error probability (PEP) of a greedy detector (GD) with maximal ratio combining (MRC) is derived. The presented results show that the performance of the GD is significantly improved when MRC diversity is employed. The proposed hybrid scheme is found to outperform maximum likelihood (ML) detection with a substantial reduction on the associated computational complexity.

Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles’ impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5–58 MeV carbon ions and for protons in the energy range2–17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energiesE>~ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

Detector for imaging and dosimetry of laser-driven epithermal neutrons by alpha conversion

An epithermal neutron imager based on detecting alpha particles created via boron neutron capture mechanism is discussed. The diagnostic mainly consists of a mm thick Boron Nitride (BN) sheet (as an alpha converter) in contact with a non-borated cellulose nitride film (LR115 type-II) detector. While the BN absorbs the neutrons in the thermal and epithermal ranges, the fast neutrons register insignificantly on the detector due to their low neutron capture and recoil cross-sections. The use of solid-state nuclear track detectors (SSNTD), unlike image plates, micro-channel plates and scintillators, provide safeguard from the x-rays, gamma-rays and electrons. The diagnostic was tested on a proof-of-principle basis, in front of a laser driven source of moderated neutrons, which suggests the potential of using this diagnostic (BN+SSNTD) for dosimetry and imaging applications.