{"id":14,"date":"2007-10-04T19:39:09","date_gmt":"2007-10-05T00:39:09","guid":{"rendered":"http:\/\/www.fruechtetheory.com\/blog\/2007\/10\/04\/analysis-of-dabbs-j-w-t-et-al-%e2%80%9cgravitational-acceleration-of-free-neutrons%e2%80%9d-phys-rev-139b-pp-756-760-1965\/"},"modified":"2007-10-04T19:39:09","modified_gmt":"2007-10-05T00:39:09","slug":"analysis-of-dabbs-j-w-t-et-al-%e2%80%9cgravitational-acceleration-of-free-neutrons%e2%80%9d-phys-rev-139b-pp-756-760-1965","status":"publish","type":"post","link":"https:\/\/www.fruechtetheory.com\/blog\/2007\/10\/04\/analysis-of-dabbs-j-w-t-et-al-%e2%80%9cgravitational-acceleration-of-free-neutrons%e2%80%9d-phys-rev-139b-pp-756-760-1965\/","title":{"rendered":"Analysis of: Dabbs, J. W. T. et al, \u201cGravitational Acceleration of Free Neutrons\u201d Phys. Rev. 139B, pp. 756-760, 1965"},"content":{"rendered":"<p>The acceleration due to gravity was actually determined to be approximately 0.5 percent less than expected, from velocities at the &#8220;polycrystalline Be block&#8221;.\u00a0 It reads to me as though velocities less than what would be expected at the 14.587 cm drop from horizontal were missing after the second collimating slit, by design.\u00a0 It would be difficult to define the velocity limit perfectly, so there would have been some velocities just under, maybe even 0.5 percent under. \u00a0Barrier diffraction of a straight path would allow some of these neutrons to reach the lower counter, and &#8220;the counting rates in the lower detector were not large (200 counts\/min at the bottom of the travel and 30-MW reactor power)&#8221;.\u00a0 Also, the slow component is said to have dropped approx. 10-20 cm, quite a range, and may be partly due to single edge diffraction patterns.<br \/>\nSomething interesting about Fig. 4 in the paper relating to the &#8220;fast&#8221; component is that for the top 9 data points for &#8220;counts\/channel&#8221;, shifting the triangle to center over channel 65 would seem to be a better fit.\u00a0 With the complete set of data points used, the fit is effected by some of the higher near zero readings on the right side of the plot.\u00a0 These readings may again include neutrons directed by single edge diffraction at the edge of the barrier.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The acceleration due to gravity was actually determined to be approximately 0.5 percent less than expected, from velocities at the &#8220;polycrystalline Be block&#8221;.\u00a0 It reads to me as though velocities less than what would be expected at the 14.587 cm drop from horizontal were missing after the second collimating slit, by design.\u00a0 It would be [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-14","post","type-post","status-publish","format-standard","hentry","category-neutron-experimentation"],"_links":{"self":[{"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/posts\/14","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/comments?post=14"}],"version-history":[{"count":0,"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/posts\/14\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/media?parent=14"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/categories?post=14"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fruechtetheory.com\/blog\/wp-json\/wp\/v2\/tags?post=14"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}