A science fan who made explosive devices after being inspired by the hit television show Brainiac has been jailed for six months.
Michael Thomas, 40, was part of a group of friends who made six pipe bombs before taking them to a remote quarry in Corsham to detonate.
One of the devices was blown up inside a microwave in a re-enactment of an experiment in the show, which has been presented by Richard Hammond and comedian Vic Reeves.
However, the group forgot to detonate one of the pipe bombs and it was unwittingly carried home in an Adidas sports bag by Thomas, who placed it in his shed following the outing in 2006.
Bristol Crown Court heard Thomas separated from his wife in 2010 and on August 17 last year, she decided to clear out his shed.
Police were called when the woman, who was not named in court proceedings, spotted a copper pipe and green cord poking out from the sports bag.
Eighty homes close to the shed, described as being in a "built-up area", were evacuated for five hours while an Army bomb disposal squad used a robotic device to examine the bag.
It was taken to a remote location nearby and safely detonated, while concerned residents took shelter in a nearby supermarket.
Thomas, who is in a new relationship and the father of two young children, was arrested and admitted a charge of making an explosive substance.
Judge Michael Roach told the stock controller that those "reckless enough" to build such devices - despite not having a sinister motive - should go to prison.
"The consequence of that discovery were sufficient not only to excite the police but also the bomb squad," the judge said.
"A street had to be evacuated and people had to be looked after at a nearby supermarket. There's no doubt at all that this is a serious offence. On any view you were enormously reckless.
"I accept that there was no sinister purpose of that device but the potential for it being on a street, unguarded, available in a residential area makes it obvious that the risks were significant.
"I can't ignore those risks."
Prosecuting, Nicholas O'Brien said Thomas lived with his ex-wife in a "built-up area", Kennmoor Close, in Warmley, Bristol, until 2010, when the couple separated.
"In August 2013 his wife decided to clear out the shed where she needed some space," Mr O'Brien said.
"She found a sports bag and having opened it she saw a number of pellets and a copper pipe, with green cord poking out the end."
Thomas was arrested on August 18 last year and officers who searched his computer discovered material relating to making explosives, Mr O'Brien added.
"It is serious and dangerous but really it seems to be a rather juvenile, amateur interest in explosives," he said.
Representing, Sam Jones said his client, who moved to Bridgwater, Somerset, was a hard-working family man with two children, aged two and 10 months.
Mr Jones said Thomas made the devices with a group of friends in 2006, before taking them to a quarry in Corsham to detonate.
"One was set off inside a microwave, inspired by a programme called Brainiac," Mr Jones said.
"At the end of the programme, which focused on science, various experiments were carried out in things like microwaves. It was used in an educational way.
"That was really the catalyst for what followed."
Mr Jones said one of the devices made a loud bang when it was blown up, but the others simply fizzed and smoked.
As Thomas, who wore a smart black suit, was led to the cells, the judge told him: "What a sad day for your family."