Sir Arthur Vandelem
Sir Arthur Vandelem was a scientist who living during the late Sixth Age, who specialized in high-energy particle physics. His experiments led to the creation of the Vandelem Bomb, which killed hundreds of millions of civilians and caused incalculable damage. Vandelem Radiation, a unique side effect of the bomb, was chiefly to blame.
Vandelem was born into a GS Town, in A.Y. 6946. The Kamian Succession Wars had been raging for centuries by that time, so like many youths, he attended a Junior Academy. While recognized as bright and very talented, Vandelem lacked the physical acumen for military service, and did not enlist in the Crimson Blade. However, he was admitted to one of the universities operated by the Foundation, where he studied nuclear physics and particle physics.
A gifted student, Vandelem was granted access to an educational extension program and eventually earned a doctorate in high-energy particle physics. He was subsequently hired by the Foundation and worked at the Giga Collider facility for several years. Vandelem was able to institute changes at the facility that led to a marked increase in productivity, which led to him being provided with his own labratory, including a supercollider of his own design that was able to produce much higher-energy collissions than most research-colliders available at the time.
It being the height of the Kamian Succession Wars, Vandelem was of course tasked with developing weapons. Being an expert in exceptionally high-energy reactions, he had actually conceived the bomb that would make him infamous while still in school, and was keen to get a prototype out. The weapon, which he named The Vandelem Bomb, was first tested in A.Y. 6491.
The Mark I test was successful in it's primary goal, but considered "horrific" in it's application. The Blind Consul ruled that they would not be using Vandelem's completed design, but allowed him to continue working on a Mark II. Speculation is that the weapon would be held in reserve or used for attacks on Kamian Homeworlds without the knowledge of the general population.
Mark II Fiasco
Vandelem's basic concept was sound, but his own execution involved scaling the device as much as conceivably possible. This required the use of higher and higher-energy reactions, and ultimately the accident which would make Vandelem infamous. The Mk 1 had a very small effective radius, equivalent to a conventional nuclear device. The Mk 2 was designed to be variable; the effect instead expanded exponentially.