In Situ Observations of Blistering of a Metal Irradiated with 2-MeV Protons

Abstract

A vacuum-insulated tandem accelerator was used to observe in situ blistering during 2-MeV proton irradiation of metallic samples to a fluence of up to 6.7 × 10 20 cm −2 . Samples consisting of copper of different purity, tantalum and tantalum-copper compounds were placed on the proton beam path and forced to cool. The surface state of the samples was observed using a charge-coupled device camera with a remote microscope. Thermistors, a pyrometer and an infrared camera were applied to measure the temperature of the samples during irradiation. After irradiation, the samples were analyzed on an X-ray diffractometer, laser and electron microscopes. The present study describes the experiment, presents the results obtained and notes their relevance and significance in the development of a lithium target for an accelerator-based neutron source, for use in boron neutron capture therapy of cancer.

A Review of Boron Neutron Capture Therapy: Its History and Current Challenges

“…Their Alphabeam system includes customizable neutron sources from a fixed beam with beam-shaping assembly, and ceiling-mount robotic couch for patient positioning. It is based on developments from the Russian Budker Institute [ 46 , 47 ] into a state-of-the-art ABNS named Alphabeam. This system consists of a negative ion source, pre-accelerator, tandem accelerator, high-energy beam lines and neutron production targets as part of the neutron beam system.…”

Neutron Source Based on Vacuum Insulated Tandem Accelerator and Lithium Target

“…"Unfortunately, while the 7 Li(p,n) 7 Be reaction is excellent neutronically, the mechanical, chemical, and thermal properties of lithium metal make it a poor candidate for a target", as previously was written in [17] (p. 23). Fortunately, all technical problems have been solved [18][19][20][21] and a lithium target has been developed that provides long-term stable neutron generation with relatively simple and safe maintenance.…”

“…The neutron source with specialized targets makes it possible to generate monochromatic γ-quanta [21] and resonance γ-quanta for the development of operational methods of explosives and drugs detection [46], α-particles for investigating promising neutron-less fusion 11 B(p,α)αα reaction [47], and positrons through 19 F(p,αe + e − ) 16 O reaction [48].…”

Исследование влияния пространственного заряда на транспортировку 2 MeV пучка протонов в ускорительном источнике эпитепловых нейтронов

“…Установлено, что пирометр Optris CT Laser 3ML SF занижает температуру из-за большой области измерения -19 mm и отсутствия технической возможности установить коэффициент эмиссии меньше 0.1, характерного для поверхности полированной меди. Инфракрасная камера FLIR T650SC, наоборот, завышает показания температуры из-за нетеплового свечения, обусловленного люминисценцией меди под действием высокоэнергетичных протонов, которое в работе про изучение блистеринга [10] было охарактеризовано как изменение коэффициента черноты поверхности меди под действием пучка протонов. Также программное обеспечение камеры не позволяет оцифровывать результаты измерений температуры без вмешательства встроенного алгоритма автокалибровки.…”