Update to Question 8-- good info from Hamamatsu

From: Hans Jostlein (jostlein@fnal.gov)
Date: Thu Jun 30 2005 - 14:32:34 CDT

I have now received a communication fro Hamamatsu , via Terri Carrol of

Here is her (?) response.
These tubes are extremely rugged!
Vibration Test (Package Goods)

Modulation Width: 7.35 m/s2 (0.75G)
Frequency: 5 Hz to 100 Hz
Sweep Speed: 20 min/sweep
Duration: 1 h/axis
Vibration Axis: 3 axes

Fall Test (Package Goods)

Height: 80 cm
Falling Position Corner: 1
                        Edge: 3
                    Surface: 6

Again, this test was done within package and only for shock and vibration
during the transit, not tested for the tube itself. Basically this size of
tube should take care very carefully and didn't expect stronger shock and
vibration than this test.
FYI, the package is only contain the tube and not contain the assy or cable.

Since concerns were voiced by Braidwood collaborators about damage or
changes to the internal parts of a PMT (as opposed to glass breakage),
I suggest to add the following text to answer 8.3, following the current

" Hamamtsu model R5912 PMT's , as proposed for the Braidwood detectors,
are designed to
survive an 80 cm drop of the shipping package (Hamamtsu private
It is not easy to derive a maximum acceleration value from this, as it
depends on the construction of the shipping package.
If we assume, extremely conservatively, a 5 cm compression of the shipping
material on impact,
 then the acceleration at impact will be 20 g, in any direction.
 This represents a safety factor of 10 if dynamic accelerations during the
detector move are held to under 1 g."

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