{"id":2401,"date":"2020-03-20T12:06:20","date_gmt":"2020-03-20T16:06:20","guid":{"rendered":"http:\/\/www.nuclearphysicslab.com\/npl\/?page_id=2401"},"modified":"2020-03-20T22:12:51","modified_gmt":"2020-03-21T02:12:51","slug":"cw-b-dot-measurement","status":"publish","type":"page","link":"http:\/\/www.nuclearphysicslab.com\/npl\/npl-home\/accelerators\/betatrons\/cw-b-dot-measurement\/","title":{"rendered":"CW B-Dot Measurement"},"content":{"rendered":"\n

Since the pulsed measurements were challenged with many systematics as well as unknown shot-to-shot variations, I rethought the measurement process. In this approach I drive the betatron coil with a CW sine wave current at 10kHz and draw a pickup coil along a radial path, recording peak-to-peak voltage induced on it.<\/p>\n\n\n\n

Instead of building yet another B-Dot probe board, I returned to the first PCB B-Dot probe of 100 turns per coil, using only the first coil and leaving the others unterminated. The first coil’s output was connected to the input of a digital oscilloscope with an internal measure function which would automatically track the peak-to-peak voltage of the pickup probe. The oscilloscope was set to average the signals over sixteen sweeps.<\/p>\n\n\n\n

\"\"<\/a>
CW driven B-Dot measurement setup.<\/figcaption><\/figure>\n\n\n\n

The betatron coil’s excitation current was generated by a 10kHz function generator driving a Kepco Bi-Polar operational amplifier for a peak current of approximate 10 Amps through the windings. This current was sufficient to induce up to 200mV voltage on the B-dot winding.<\/p>\n\n\n\n

The B-dot probe board was cantilevered off a the carriage of a 11-inch travel, hand driven, Velmex slide. The Velmex slide was mounted to two scissor jacks to position both the vertical hight and inclination of the B-dot probe board. Two heigh gauges were used to align the board to travel in the betatron coil’s median plane.<\/p>\n\n\n\n

Data was taken by manually sliding the B-Dot probe along the radial path in 0.5 inch increments and recording the induced voltage each.<\/p>\n\n\n\n

\"\"
Data from the CW measurement.<\/figcaption><\/figure>\n\n\n\n

Comparison to previous measurements:<\/p>\n\n\n\n

\"\"
Comparison of measurements.<\/figcaption><\/figure>\n\n\n\n

Profile looks correct, but why 2\/3 the peak center field? The mystery continues.<\/p>\n","protected":false},"excerpt":{"rendered":"

Since the pulsed measurements were challenged with many systematics as well as unknown shot-to-shot variations, I rethought the measurement process. In this approach I drive the betatron coil with a CW sine wave current at 10kHz and draw a pickup coil along a radial path, recording peak-to-peak voltage induced on it. Instead of building…<\/p>\n

Read More Read More<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"parent":151,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"advanced-sidebar-menu\/link-title":"","advanced-sidebar-menu\/exclude-page":false},"categories":[10,14,79,37],"tags":[],"_links":{"self":[{"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/pages\/2401"}],"collection":[{"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/comments?post=2401"}],"version-history":[{"count":3,"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/pages\/2401\/revisions"}],"predecessor-version":[{"id":2622,"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/pages\/2401\/revisions\/2622"}],"up":[{"embeddable":true,"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/pages\/151"}],"wp:attachment":[{"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/media?parent=2401"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/categories?post=2401"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.nuclearphysicslab.com\/npl\/wp-json\/wp\/v2\/tags?post=2401"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}