Radiation damage in ion-implanted quartz crystals. Part I: Nuclear and electronic energy deposition

Abstract

The disorder formation in quartz crystals by implantation of He+, B+, and Ar+ ions at room temperature is investigated by Rutherford‐backscattering spectrometry (RBS). The efficiency of the process of damage production is strongly dependent on the energy deposition mechanism and the degree of disorder. Three characteristic stages of defect formation are found in dependence on nuclear deposited energy density Gn: (I) Point defects are produced at Gn ≦ 1 × 1020 keV/cm3. (II) Amorphous microregions are generated up to the formation of a quasi amorphous layer (termed “RBS‐amorphous”) at Gn ≅ 2.5 × 1020 keV/cm3. (III) Further structural changes occur in RBS‐amorphous layers at larger Gn values. Disorder formation due to electronic processes is possible, but only in predamaged quartz, and at a very low efficiency.

Nature of radiation-induced defects in quartz

“…It is widely used in engineering applications, e.g., in construction materials, semiconductors, integrated optics, ultrasonic devices, etc. [1][2][3][4][5]. Many of these applications require the material to withstand exposure to radiations.…”

“…Numerous experimental studies have been conducted to assess the nature and extent of damage induced in quartz by various types of irradiations, and often using neutrons and different types of ions [1,5,[9][10][11][12][13]. It is generally admitted that different types of irradiation result in similar damage to the atomic structure [12].…”

“…It is generally admitted that different types of irradiation result in similar damage to the atomic structure [12]. Such damage has been described in term of an accumulation of point defects, which eventually causes structural amor-phization [1,11]. However, the final amorphized structure is found to be different from that of glassy silica, and the detailed nature of the formed point defects has not been clearly identified [10,11].…”

“…However, the final amorphized structure is found to be different from that of glassy silica, and the detailed nature of the formed point defects has not been clearly identified [10,11]. Numerous studies have focused on the oxygen vacancies created during irradiation [1,[14][15][16]. Indeed, it is well-known that the oxygen vacancies present in quartz after ionization or electronic radiations can trap electrons, forming the so-called E center, a color center that modifies the optical properties of quartz [17].…”

Irradiation damage in inorganic insulation materials for ITER magnets:

“…The nature of the local disorder was not determined. Fischer et al [1983a] also studied the formation of disorder in quartz. They used RBS to investigate the degree of disorder by implantation of He'*', B'*', and…”