[time-nuts] Re: Trinity Timing - How far we've come

[Tom Van Baak]

For those of you who have just watched Oppenheimer, here is a classic 
posting from 2008 that deserves fresh exposure [1]:

 > From: "Neon John" <jgd at johngsbbq.com>
 > To: time-nuts
 > Sent: Wednesday, March 12, 2008 5:27 AM
 > Subject: [time-nuts] Trinity Timing - How far we've come
 >
 > In this paper
 >
 > http://www.sciencemadness.org/lanl1_a/lib-www/la-pubs/00350316.pdf
 >
 > you can read the detailed description (including schematics) of the 
high accuracy
 > timing system built to control the Manhattan Project's Trinity test - 
the first
 > nuclear device explosion.
 >
 > This is an absolutely fascinating read.  It is stunning what they did 
with the
 > materials at hand and especially in the short time frame between when 
the Gadget was
 > fairly certain to work and the test explosion.
 >
 > The site time reference standard was, for example, a 1khz tuning 
fork!  Yet they
 > managed to time certain critical events to better than 0.1 
microsecond and do so
 > despite having to drive miles of transmission line. Remarkable.
 > ...

The 35 page now-unclassified PDF that John points to is still accessible 
at that URL. It's a must-read for time nuts, especially if you're old 
enough to have worked with vacuum tubes, or know about fast thyratron 
switches [2] like the 4C35, or are just curious how nanoseconds timing 
was done 75 years ago.

In a similar era, the hp 212A used a pair of hydrogen thyratrons [3], 
see schematics [4]. The RadLab pulse book [5] has more examples.

The paper was written by British physicist Ernest Titterton [3] [4] in 
1946 about the 1945 Trinity test. It looks like he was the "time nut" 
for the experiment. If that doesn't get your attention here are some 
keywords: "pulse rising 300 volts in less than 0.1 microsecond", "1000 
yds of RG9U coaxial cable", "sawtooth generators and discriminators", 
"hp 200C", "1 kc tuning fork frequency standard", Lissajou, "4C35 
thyratron", "counter chronograph", interpolation, "detonator line 
driver", "output amph. 80-C to Raytheon Unit on top of Tower".

Aside from a thousand other details of the Manhattan project, precise 
timing was a critical [sic] requirement.

/tvb

[1] 
https://febo.com/pipermail/time-nuts_lists.febo.com/2008-March/012789.html

[2] https://en.wikipedia.org/wiki/Thyratron

[3] https://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1950-02.pdf

[4] http://hparchive.com/Manuals/HP-212A-Manual.pdf

[5] https://www.febo.com/pages/docs/RadLab/VOL_5_Pulse_Generators.pdf

[6] https://ahf.nuclearmuseum.org/ahf/profile/ernest-w-titterton/

[7] https://en.wikipedia.org/wiki/Ernest_Titterton