N.I. Balalykin

RBS study of amorphous silicon carbide films deposited by PECVD

We present properties of nitrogen-doped amorphous silicon carbide films that were grown by a plasma enhanced chemical vapour deposition (PECVD) technique and annealed by pulsed electron beam. Samples with different amounts of N were achieved by a small addition of ammonia NH3 into the gas mixture of silane SiH4 and methane CH4, which were directly introduced into the reaction chamber. The actual amount of nitrogen in the SiC films was determined by Rutherford backscattering spectrometry (RBS). A simulation of the RBS spectra was used to calculate the concentration of carbon, silicon and nitrogen.

Laser Driver for a Photoinjector of an Electron Linear Accelerator (February 2014)

The presented laser driver for a photoinjector of an electron linear accelerator delivers 10-ps long laser pulses with the energy of 1.85 μJ at the wavelength of 262 nm. Laser pulses irradiating with the repetition rate of 10 MHz form the rectangular 800-μ s long pulse trains with 18.5-W mean power inside them. The pulse train repetition rate is 10 Hz. Short-lived absorption centers accumulating in BBO fourth-harmonic generator crystal cause significant distortion of the pulse train envelope. The envelope remains rectangular due to precompensating of these distortions in the fiber acousto-optical modulator with fast varying transmission.

Physical and bonding characteristics of N-doped hydrogenated amorphous silicon carbide films grown by PECVD and annealed by pulsed electron beam

Nitrogen-doped amorphous silicon carbide films were grown by a plasma enhanced chemical vapour deposition (PE CVD) technique. The actual amount of nitrogen in the SiC films is determined by Rutherford backscattering spectrometry (RBS). For irradiation experiments we use electron beams with a kinetic energy 200 keV, a pulse duration of 300 ns, and a beam current of 150 A/cm2. It is found that with increased nitrogen doping and following activation of dopants the resistivity of the amorphous SiC films is substantially reduced.

JINR LHEP photoinjector prototype

A photoinjector prototype for future electron–positron colliders and free-electron lasers (FEL) is being developed at the Joint Institute for Nuclear Research (JINR). A 30-keV photogun stand, transmission (backside irradiated) photocathode concept, and stand investigations of such cathodes in collaboration with Institute of Electrical Engineering (IEE SAS) (Bratislava, the Slovak Republic) are described. A progress report on creating the photoinjector at an electron energy of up to 400 keV with a unique 10-ps laser driver is given.

PECVD nitrogen doped a-SiC:H films: properties

We present properties of nitrogen-doped amorphous silicon carbide films grown by PECVD and annealed by a pulsed electron beam. Samples with different amounts of N were achieved by a small addition of ammonia NH/sub 3/ into the gas mixture of silane SiH/sub 4/ and methane CH/sub 4/, which were directly introduced into the reaction chamber. A simulation of the RBS spectra was used to calculate the concentration of carbon, silicon and nitrogen. The current-voltage (I-V) characteristics of diodes made of doped and irradiated SiC films grown on silicon substrates were studied.

Study of the transmissive photocathode DC gun based on diamond-like films at JINR

Development of the original transmissive photocathode conception is going on in JINR. Results of charge extraction from thin-film diamond-like carbon (DLC) photocathodes are presented. DLC films were prepared using both methods of reactive magnetron sputtering of carbon target in the mixture of Ar and H2(D2) gases and vapor deposition CH4+D2(H2)+Ar.

Photocathode based on deuterated diamond like carbon films prepared by reactive magnetron sputtering and PECVD technology

The influence of deuterated diamond like carbon films technology and properties on quantum efficiency of prepared photocathode has been investigated. Deuterated diamond like carbon films were deposited on silicon substrate and stainless steel mesh by PECVD from gas mixture CH4 and D2 and reactive magnetron sputtering using carbon target and gas mixture Ar and D2. The concentration of elements in films was determined by RBS and ERD. Chemical compositions were analyzed by FT-IR. Raman spectroscopy at visible excitation wavelength was used for I(D)/I(G) ratio determination. The quantum efficiency was calculated from the measured laser energy and the measured cathode charge.

On radiation protection at the LINAC-800 linear electron accelerator

The Automatic System of Radiation Safety Control (ASRSC) of the LINAC-800 linear electron accelerator is designed to ensure radiation safety for accelerator personnel during regular operations and in emergency cases. The results of calculating the emission power used to develop the ARPS are given. Both hardware and software components of the radiation control system are described. This paper also presents a description of the interlock and signalization system.

Nanocrystalline diamond/amorphous composite carbon films prepared by PECVD technology for photocathode application

Nanocrystalline diamond/amorphous composite carbon films were deposited by plasma enhanced chemical vapour deposition method. The concentrations of species in the films were determined by RBS (Rutherford backscattering spectrometry) and ERD (elastic recoil detection) methods. The RBS results showed the main concentrations of C in the films. The concentration of hydrogen was approximately 20 at.%. Chemical compositions were analyzed by FTIR spectroscopy. IR results showed the presence of C-H specific bonds. Film was used for photocathode application. The original quantum efficiency of prepared photocathode at energy of FH 15,6 mJ was 1,43×10−6 %.

Control system of injector for linear electron accelerator LINAC-800

This paper describes the control system of the injector for the LINAC-800 linear electron accelerator. The architecture of the control system, the equipment, and software are presented. This system is part of the first segment of the control system of the LINAC-800 electron accelerator.