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<div>We considered this and other compounds of tunsten for the Qweak collimator. What we decided upon is the matetial I suggested to Kent for PREX. It is inexpensive, machinable, can be easily brazed (so you can attach a water cooling jacket) and ONLY composed of Cu and Tungsten. These other composites are very expensive, not easy to machine and more importantly have other elements that might screw up a PV measurement.</div><div><br></div><div>Roger</div><div><br></div><div><br></div><div><br></div><div id="composer_signature"><div style="font-size:88%;color:#364f67" dir="auto">Sent from my Verizon 4G LTE smartphone</div></div><br><br>-------- Original message --------<br>From: Jay Benesch <benesch@jlab.org> <br>Date: 10/20/18 5:07 AM (GMT-08:00) <br>To: moller@jlab.org, Greg Smith <smithg@jlab.org> <br>Subject: [Moller] new collimator material? <br><br>90W10Cu might still be preferred, but someone competent might glance at <br>these articles in Nature<br><br><br>https://www.nature.com/articles/d41586-018-07005-9<br><br>The final object is formed of approximately 58% ZrC ceramic and 36% <br>tungsten metal, with small amounts of residual tungsten carbide and <br>copper. The beauty of the method is that the porous preform is converted <br>into a non-porous ZrC/tungsten composite of the same dimensions (the <br>overall volume change is approximately 1–2%).<br><br><br>https://www.nature.com/articles/s41586-018-0593-1<br>Ceramic–metal composites for heat exchangers<br><br>Here we present a robust composite of ceramic (zirconium carbide, ZrC) <br>and the refractory metal tungsten (W) for use in printed-circuit-type <br>heat exchangers at temperatures above 1,023 kelvin9. This composite has <br>attractive high-temperature thermal, mechanical and chemical properties <br>and can be processed in a cost-effective manner.<br>_______________________________________________<br>Moller mailing list<br>Moller@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/moller<br></body></html>