http://news.bbc.co.uk/2/hi/science/nature/4598955.stm?top
Drawing uncovered of 'Nazi nuke'

The diagram appears in an undated report about nuclear weapons work in
Nazi Germany

Historians working in Germany and the US claim to have found a
60-year-old diagram showing a Nazi nuclear bomb.
It is the only known drawing of a "nuke" made by Nazi experts and
appears in a report held by a private archive.

The researchers who brought it to light say the drawing is a rough
schematic and does not imply the Nazis built, or were close to
building, an atomic bomb.

But a detail in the report hints some Nazi scientists may have been
closer to that goal than was previously believed.

The Nazis were far away from a 'classic' atomic bomb. But they hoped
to combine a 'mini-nuke' with a rocket

Rainer Karlsch

The report containing the diagram is undated, but the researchers
claim the evidence points to it being produced immediately after the
end of the war in Europe. It deals with the work of German nuclear
scientists during the war and lacks a title page, so there is no
evidence of who composed it.

One historian behind the discovery, Rainer Karlsch, caused a storm of
controversy earlier this year when he claimed to have uncovered
evidence the Nazis successfully tested a primitive nuclear device in
the last days of WWII. A number of historians rejected the claim.

The drawing is published in an article written for Physics World
magazine by Karlsch and Mark Walker, professor of history at Union
College in Schenectady, US.

'Mini-nuke'

The newly uncovered document was discovered after the publication of
Karlsch's book, Hitlers Bombe (Hitler's Bomb), in which he made the
nuclear test claim.

"The Nazis were far away from a 'classic' atomic bomb. But they hoped
to combine a "mini-nuke" with a rocket," Dr Karlsch told the BBC News
website.

"The military believed they needed around six months more to bring the
new weapon into action. But the scientists knew better how difficult
it was to get the enriched uranium required."

The head of Nazi Germany's nuclear energy programme was the physicist
Werner Heisenberg. Though he was highly accomplished in other areas of
physics, Heisenberg failed to understand a key aspect of nuclear
fission chain reactions.

Heisenberg's uncertainty

Some researchers say this led him to overestimate the amount of
uranium - the so-called fissile material - required to build a nuclear
bomb.


Hitler was desperate for weapons that would turn the tide of the war
However, the German report contains an estimate of slightly more than
5kg for the critical mass of a plutonium bomb. This is comparatively
close to the real figure and may suggest some Nazi scientists had a
better grasp of nuclear fission than Heisenberg.

Professor Paul Lawrence Rose of Pennsylvania State University, US, and
author of a 1998 book about the German uranium programme, said he had
no reason to believe the report was not genuine, but was dubious about
the significance of the critical mass detail.

"Though it's wonderful to find the 5kg figure written on the document,
one has to be sceptical about the rationale for it. Even if it's true
and [some scientists] did understand it, Heisenberg's group wouldn't
have accepted it," Rose told the BBC News website.

He further speculated it was possible the author arrived at this
figure by reading the Smyth Report into the development of the US
atomic bomb, which was published in July 1945. But Karlsch and Walker
reject this claim.

Bombshell claim

In Hitlers Bombe, Dr Karlsch suggests a team of scientists directed by
the physicist Kurt Diebner, which was in competition with Heisenberg's
group, tested a primitive nuclear device in Thuringia, eastern
Germany, in March 1945.

Rose says that this is unlikely. Transcripts of conversations taped by
MI6 when the scientists were held captive in England after the war
show Diebner lacked the knowledge to have done this, he claims.

"Karlsch revealed some very important details in his book, but I can't
go along with the picture he constructs with those details - of a Nazi
nuclear test," said Professor Dieter Hoffmann of the Max Planck
Institute for the History of Science in Berlin.

But in their Physics World article, Karlsch and Walker point to
evidence of innovations made by Diebner's team, including a nuclear
reactor design superior to that produced by Heisenberg's group.

"[Diebner] got the research papers from all other groups and he could
control the information flux. Only a few scientists around Diebner
knew about his bomb project. Heisenberg was not aware of it," Dr
Karlsch explained.

http://news.bbc.co.uk/2/hi/science/nature/4598955.stm?top
Drawing uncovered of 'Nazi nuke'

The diagram appears in an undated report about nuclear weapons work in
Nazi Germany

Historians working in Germany and the US claim to have found a
60-year-old diagram showing a Nazi nuclear bomb.
It is the only known drawing of a "nuke" made by Nazi experts and
appears in a report held by a private archive.

The researchers who brought it to light say the drawing is a rough
schematic and does not imply the Nazis built, or were close to
building, an atomic bomb.

But a detail in the report hints some Nazi scientists may have been
closer to that goal than was previously believed.

The Nazis were far away from a 'classic' atomic bomb. But they hoped
to combine a 'mini-nuke' with a rocket

Rainer Karlsch

The report containing the diagram is undated, but the researchers
claim the evidence points to it being produced immediately after the
end of the war in Europe. It deals with the work of German nuclear
scientists during the war and lacks a title page, so there is no
evidence of who composed it.

One historian behind the discovery, Rainer Karlsch, caused a storm of
controversy earlier this year when he claimed to have uncovered
evidence the Nazis successfully tested a primitive nuclear device in
the last days of WWII. A number of historians rejected the claim.

The drawing is published in an article written for Physics World
magazine by Karlsch and Mark Walker, professor of history at Union
College in Schenectady, US.

'Mini-nuke'

The newly uncovered document was discovered after the publication of
Karlsch's book, Hitlers Bombe (Hitler's Bomb), in which he made the
nuclear test claim.

"The Nazis were far away from a 'classic' atomic bomb. But they hoped
to combine a "mini-nuke" with a rocket," Dr Karlsch told the BBC News
website.

"The military believed they needed around six months more to bring the
new weapon into action. But the scientists knew better how difficult
it was to get the enriched uranium required."

The head of Nazi Germany's nuclear energy programme was the physicist
Werner Heisenberg. Though he was highly accomplished in other areas of
physics, Heisenberg failed to understand a key aspect of nuclear
fission chain reactions.

Heisenberg's uncertainty

Some researchers say this led him to overestimate the amount of
uranium - the so-called fissile material - required to build a nuclear
bomb.


Hitler was desperate for weapons that would turn the tide of the war
However, the German report contains an estimate of slightly more than
5kg for the critical mass of a plutonium bomb. This is comparatively
close to the real figure and may suggest some Nazi scientists had a
better grasp of nuclear fission than Heisenberg.

Professor Paul Lawrence Rose of Pennsylvania State University, US, and
author of a 1998 book about the German uranium programme, said he had
no reason to believe the report was not genuine, but was dubious about
the significance of the critical mass detail.

"Though it's wonderful to find the 5kg figure written on the document,
one has to be sceptical about the rationale for it. Even if it's true
and [some scientists] did understand it, Heisenberg's group wouldn't
have accepted it," Rose told the BBC News website.

He further speculated it was possible the author arrived at this
figure by reading the Smyth Report into the development of the US
atomic bomb, which was published in July 1945. But Karlsch and Walker
reject this claim.

Bombshell claim

In Hitlers Bombe, Dr Karlsch suggests a team of scientists directed by
the physicist Kurt Diebner, which was in competition with Heisenberg's
group, tested a primitive nuclear device in Thuringia, eastern
Germany, in March 1945.

Rose says that this is unlikely. Transcripts of conversations taped by
MI6 when the scientists were held captive in England after the war
show Diebner lacked the knowledge to have done this, he claims.

"Karlsch revealed some very important details in his book, but I can't
go along with the picture he constructs with those details - of a Nazi
nuclear test," said Professor Dieter Hoffmann of the Max Planck
Institute for the History of Science in Berlin.

But in their Physics World article, Karlsch and Walker point to
evidence of innovations made by Diebner's team, including a nuclear
reactor design superior to that produced by Heisenberg's group.

"[Diebner] got the research papers from all other groups and he could
control the information flux. Only a few scientists around Diebner
knew about his bomb project. Heisenberg was not aware of it," Dr
Karlsch explained.