<html><head></head><body>Beni,<div><br></div><div>Below is the info on the Hamamatsu PMT magnetic shield. </div><div><br></div><div><br></div><div><div><b>Magnetic Shield Cases E989 Series</b></div><div><br></div><div>Photomultiplier tubes are extremely sensitive to magnetic fields and exhibit output variations even from sources such as terrestrial magnetism.</div><div>Hamamatsu E989 series magnetic shield cases are designed specifically to protect photomultiplier tubes from the influence of such magnetic fields. </div><div>The E989 series uses permalloy, a material that has an extremely high permeability (approximately 105). </div><div>The magnetic field intensity within the shield case can be attenuated from 1/1000 to 1/10000 of that outside the shield case (this ratio is called the shielding factor). </div><div>The E989 series ensures a stable output for photomultiplier tubes operating in proximity to magnetic fields.</div><div><b><br></b></div><div><b>Features</b></div><div><b>* Made of high-permeability permalloy (Ni: 78 %, Fe and others: 22 %)</b></div><div><b></b><b>* Various sizes available with inner diameters from 12 mm to 138 mm</b></div><div><b></b><b>* Lusterless black paint finish</b></div></div><div><br></div><div><br><div>
<div><div><div>--</div><div>Prof. Paul Eugenio</div><div>Florida State University</div><div>Department of Physics</div><div>Tallahassee, Florida, USA 32306</div><div><br></div><div>(850) 644-2585</div><div><a href="mailto:eugenio@fsu.edu">eugenio@fsu.edu</a></div><div><br></div></div></div><br class="Apple-interchange-newline">
</div>
<br></div></body></html>