Miscellaneous rohacell properties

To: senta.v.greene@vanderbilt.edu (S. Victoria Greene)
Subject: Re: rohacell query

Hi Vicky,

I lifted some of the the information below from

Supplier: Rohm Tech Inc., 195 Canal Street, Malden, MA 02148, USA. 
Tel:617.321.6984, Fax:617.322.0358. 

Chemistry: it is a polymethacrylimide foam, see

radiation length, 5,450 mm


The CDF experiment at Fermi National Laboratory used Rohacell as the support
structure for their silicon tracker:
D. Amidei, et. al., Nucl. Instr. and Meth. A 350(1994)98. 

There are six different grades of Rohacell, Rohacell 31, 51, 71, 110, 170,
190, each increasing in density. Rohacell 71 was chosen for the MVD because it
best matched our needs for lowest density at highest strength. It has a
density of 75 kg/m3 (4.7 lbs/ft3), a tensile strength of 270 PSI, and a low
coefficient of linear thermal expansion, measuring 3.3x10-5 K-1 . Rohacell is
hygroscopic and tends to expand with increasing relative humidity.

The following rad hardness info is from

Richmond Aircraft Products states that the "compressive test specimens
50x50x30mm3 and the flexural test specimens 100x10x10 mm3 were irradiated with
a dose of 0.15 Mrad and 10 Mrad from a cobalt 60 source." The table concludes
that there was "no significant decrease in the tested properties up to a dose
of 0.15 Mrad."


The IU Atlas project at CERN had conducted tests on Rohacell 31. They found
that at exposures above 9.2 Mrad rohacell "completely gave out and could not
hold any more weight." This only happened after they subjected the exposed
rohacell sample to over 400 grams of weight. [Radiation test on Transition
Radiation Materials, H. Orgen, et. al., February 29, 1996,
needmore.physics.indiana.edu/~fred/iu_atlas/iu_atlas.html]


                    I hope this is what you were looking for
                            cheers, Hubert

======================================================================
> 
> 
> Dear Hubert,
> 
> I just got a query from Bruce Libby wanting some info about rohacell.  I
> found the radiation length on your web site, but not the composition and
> density.  Can you help?
> Thanks,
>    Vicki