Characterization of CVD Diamond Films Used for Radiation Detection.

1994 ◽  
Vol 339 ◽  
Author(s):  
F. Foulon ◽  
T. Pochet ◽  
E. Gheeraert ◽  
A. Deneuville
Keyword(s):  
Carrier Mobility ◽  
Microwave Plasma ◽  
Radiation Detection ◽  
Diamond Films ◽  
Radiation Detectors ◽  
Cvd Diamond ◽  
Alpha Particles ◽  
Photon Flux ◽  
Detector Response ◽  
X Ray

ABSTRACTDiamond films produced by microwave plasma enhanced chemical vapor deposition (CVD) technique and used to fabricate radiation detectors have been characterized. The polycrystalline diamond films have a measured resistivity of 1012 Ω.cm and a carrier lifetime of about 530 ps. The carrier mobility - lifetime product depends on the density of photogenerated carriers. The carrier mobility decreases from 160 to 13 cm2/V.s for a carrier density increase from 2 × 1011 cm-3 to 3.7 × 1013 cm-3. The detector response to laser pulses (λ= 355, 532 and 1064 nm), X-ray flux (2.5 – 16 keV) and alpha particles (241Am, 5.49 MeV) has been investigated. The response speed of the detector is in the 100 ps range. X-ray photon flux measurements and alpha particle counting capabilities of the CVD diamond detectors are demonstrated.

scholarly journals Design, fabrication and testing of diamond radiation detectors for charged particle and neutron detection

2017 ◽  
Author(s):  
◽  
Haruetai Kasiwattanawut
Keyword(s):  
Charged Particle ◽  
Radiation Detection ◽  
Chemical Vapor ◽  
Radiation Detectors ◽  
Cvd Diamond ◽  
Alpha Particles ◽  
Energy Calibration ◽  
Beta Radiation ◽  
Host Materials ◽  
Current Voltage

In this work, the single crystal Chemical Vapor Deposition (CVD) diamond detectors were designed and fabricated to investigate and detect any possible charged particle and neutron emissions from gas-phase Low Energy Nuclear Reaction (LENR) experiments at room temperature. The diamond detectors were used in two experimental gas loading systems, palladium-deuterium, and nickel hydrogen. Palladium and nickel were used as host materials. Thin film layers of Ti/Pd and Ti/Pt/Au/Ni were deposited on the CVD diamond plates by evaporation techniques to create an Ohmic contact. Electronic characterizations of the detectors were completed by current-voltage measurements and energy calibration with alpha particles. The simulation and experimental run of the diamond detector with alpha and beta radiations exposures were done to determine the response of the detector to charged particles. The experimental results show that the diamond detectors observed and detected significant signal bursts from the gas loading experiments. The results from this work demonstrate that diamond detectors are suitable for alpha and beta radiation detection.

Crystalline perfection of chemical vapor deposited diamond films

1990 ◽  
Vol 5 (8) ◽  
pp. 1591-1594 ◽  
Author(s):  
A. V. Hetherington ◽  
C. J. H. Wort ◽  
P. Southworth
Keyword(s):  
Grain Boundaries ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Stacking Faults ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Growth Conditions ◽  
Crystalline Perfection ◽  
Planar Defects ◽  
Chemical Vapor Deposited

The crystalline perfection of microwave plasma assisted chemical vapor deposited (MPACVD) diamond films grown under various conditions has been examined by TEM. Most CVD diamond films thus far reported contain a high density of defects, predominantly twins and stacking faults on {111} planes. We show that under appropriate growth conditions, these planar defects are eliminated from the center of the crystallites, and occur only at grain boundaries where the growing crystallites meet.

Single Crystal CVD Diamond Nuclear Detectors

2006 ◽  
Vol 48 ◽  
pp. 103-112 ◽  
Author(s):  
Claudio Manfredotti
Keyword(s):  
Single Crystal ◽  
Time Derivative ◽  
Diamond Films ◽  
Radiation Detectors ◽  
Cvd Diamond ◽  
High Energy ◽  
Neutron Spectrometry ◽  
Free Standing ◽  
Wide Range ◽  
Nuclear Detectors

CVD diamond films have reached in recent years superlative improvements in their “ detector grade “ quality, with a time derivative which was never registered for other similar frontier materials. The basic properties of high quality CVD diamond films make them very interesting for a wide range of radiation detectors : they provide fast signals with very low leakage currents, they are very radiation resistant, they have excellent thermal properties and they can be manufactured as free-standing detectors. The recent availability of single crystal CVD diamond samples of extreme good quality, suitable thickness and surface area has opened new application fields in nuclear detection and dosimetry, such as, for instance, hadron therapy and neutron spectrometry in fusion reactors. At the same time, strip and pixel detectors of unprecedented performances have been successfully realized and exploited in the framework of high energy physics experiments. The paper will review the more recent history of CVD diamond nuclear detectors with respect to material quality, with a particular emphasis on epitaxial single crystals diamond, and the achievements in terms of applications in some different fields.

Role of microstructure on the oxidation behavior of microwave plasma synthesized diamond and diamond-like carbon films

1990 ◽  
Vol 5 (11) ◽  
pp. 2445-2450 ◽  
Author(s):  
Rao R. Nimmagadda ◽  
A. Joshi ◽  
W. L. Hsu
Keyword(s):  
Oxidation Behavior ◽  
Microwave Plasma ◽  
Natural Diamond ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Gravimetric Analysis ◽  
Oxidation Rates

Oxidation kinetics of microwave plasma assisted CVD diamond and diamond-like carbon (DLC) films in flowing oxygen were evaluated in the temperature range of 500 to 750 °C and were compared with those of graphite and natural diamond. The diamond and DLC films were prepared using CH4/H2 ratios of 0.1, 0.25, 0.5, 1.0, and 2.0%. The films deposited at 0.1% ratio had a faceted crystalline structure with high sp3 content and as the ratio increased toward 2%, the films contained more and more fine crystalline sp2 bonded carbon. The oxidation rates were determined by thermal gravimetric analysis (TGA), which shows that the films deposited at ratios of 2, 1, and 0.5% oxidized at high rates and lie between the rates of natural diamond and graphite. The oxidation rate decreased with lower CH4/H2 ratio and the films deposited at 0.25 and 0.1% exhibited the lowest oxidation rates associated with the highest activation energies in the range of 293–285 kJ/mol · K. The oxidation behavior of microwave plasma assisted diamond films was similar to that of DC plasma assisted CVD diamond films. The results suggest that the same mechanism of oxidation is operational in both DC and microwave plasma assisted diamond films and is probably related to the microstructure and preferred orientation of the crystallites.

Local order in CVD diamond films : Comparative Raman, x-ray-diffraction, and x-ray-absorption near-edge studies

1998 ◽  
Vol 57 (22) ◽  
pp. 14123-14132 ◽  
Author(s):  
L. Fayette ◽  
B. Marcus ◽  
M. Mermoux ◽  
G. Tourillon ◽  
K. Laffon ◽  
...  
Keyword(s):  
Diamond Films ◽  
Cvd Diamond ◽  
Local Order ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Absorption

The Initial Stages of Plasma Synthesis of Diamond Films

1988 ◽  
Vol 129 ◽  
Author(s):  
R. Meilunas ◽  
M.S. Wong ◽  
K. Sheng ◽  
T.P. Ong ◽  
R.P.H. Chang
Keyword(s):  
Microwave Plasma ◽  
Diamond Films ◽  
Nucleation And Growth ◽  
Plasma Synthesis ◽  
X Ray Diffraction ◽  
Diamond Nucleation ◽  
X Ray ◽  
Deposition Parameters ◽  
Starting Conditions ◽  
Size And Morphology

ABSTRACTThe effects of plasma starting conditions on the initial stages of diamond nucleation and growth in a microwave plasma have been studied as a function of important deposition parameters. The influence of the substrate temperature on the diamond nucleation rate, quality, and final film morphology has been elucidated through various analytical measurements. The diamond films are characterized with Raman spectroscopy, X-ray diffraction, and scanning electron microscopy. Finally, methods are described for reproducibly controlling the grain size and morphology of the diamond films for tribological and abrasive applications.

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