{"id":75,"date":"2018-11-27T22:49:35","date_gmt":"2018-11-27T22:49:35","guid":{"rendered":"http:\/\/uni.hi.is\/martin\/?p=75"},"modified":"2018-12-07T14:45:03","modified_gmt":"2018-12-07T14:45:03","slug":"thokuklefaraunir","status":"publish","type":"post","link":"https:\/\/uni.hi.is\/martin\/2018\/11\/27\/thokuklefaraunir\/","title":{"rendered":"\u00deokuklefaraunir"},"content":{"rendered":"

Fyrsti kafli: Prologus<\/h2>\n

Mig hefur lengi dreymt um a\u00f0 setja saman \u00feokuklefa. \u00c9g man eftir a\u00f0 hafa heyrt fl\u00f6kkus\u00f6gur um a\u00f0 h\u00e6gt v\u00e6ri a\u00f0 sj\u00e1 ferla eftir geislavirkar eindir \u00ed bj\u00f3rfl\u00f6sku, en sel \u00fea\u00f0 ekki d\u00fdrar en \u00e9g keypti \u00fea\u00f0.<\/p>\n

\u00d3, en hva\u00f0 er n\u00fa \u00feokuklefi? J\u00fa, \u00feokuklefi er klefi sem k\u00e6ldur er a\u00f0 ne\u00f0an og (oft) hita\u00f0ur a\u00f0 ofan svo \u00fea\u00f0 myndast hitastigull \u00ed honum. Inni \u00ed \u00feokuklefanum er (yfirleitt) \u00eds\u00f3pr\u00f3p\u00edl alk\u00f3h\u00f3l \u00e1 v\u00f6kvaformi, oft \u00ed felti e\u00f0a \u00e1l\u00edka sem fest er vi\u00f0 hli\u00f0ar e\u00f0a topp klefans.<\/p>\n

Alk\u00f3h\u00f3li\u00f0 er rokgjarnt svo \u00fea\u00f0 gufar upp \u00fear til lofti\u00f0 er metta\u00f0 af alk\u00f3h\u00f3lgufunni. Nema hva\u00f0 leysni loftsins er minni eftir \u00fev\u00ed sem hitastigi\u00f0 l\u00e6kkar svo \u00feegar alk\u00f3h\u00f3lgufan sveimar ni\u00f0ur yfirmettast h\u00fan; \u00fe.e. h\u00fan myndar dropa strax og eitthva\u00f0 stuggar vi\u00f0 henni.<\/p>\n

Til d\u00e6mis i\u00f0ustreymi \u00ed loftinu, ryk\u00f6gn, ... j\u00e1, e\u00f0a orkur\u00edk \u00f6reind.<\/p>\n

\"Geislavirkni
Radioactivity of a Thorite mineral seen in a cloud chamber. By Cloudylabs - Own work, CC BY-SA 3.0, https:\/\/commons.wikimedia.org\/w\/index.php?curid=30489935<\/figcaption><\/figure>\n

Fyrir nokkru kom upp s\u00fa hugmynd a\u00f0 vera me\u00f0 \u00feokuklefa til a\u00f0 s\u00fdna geislavirkni \u00ed kringum berg og svo stakk S\u00e6var Helgi upp \u00e1 \u00fev\u00ed vi\u00f0 Gu\u00f0r\u00fanu a\u00f0 V\u00edsindasmi\u00f0jan keypti svona gr\u00e6ju.<\/p>\n

Annar kafli: Fyrsta f\u00e1lmun<\/h2>\n

\u00c9g f\u00f3r \u00e1 st\u00fafana til a\u00f0 sj\u00e1 hva\u00f0 til v\u00e6ri af svona gr\u00e6jum og hva\u00f0 \u00fe\u00e6r kostu\u00f0u. \u00c9g hef s\u00e9\u00f0 nokkrar \u00fatg\u00e1fur \u00e1 v\u00edsindas\u00f6fnum en \u00fe\u00e6r eru allar nokku\u00f0 f\u00e1ga\u00f0ar og kosta eflaust st\u00f3rf\u00e9. Svo hva\u00f0 me\u00f0 bara minni \u00feokuklefa?<\/p>\n

\u00dea\u00f0 kemur \u00e1 daginn a\u00f0 \u00fea\u00f0 er nokku\u00f0 au\u00f0velt a\u00f0 b\u00faa \u00feokuklefann til, eins og r\u00e1\u00f0a m\u00e1 af l\u00fdsingunni a\u00f0 ofan. \u00dea\u00f0 \u00fearf bara eitthva\u00f0 til a\u00f0 k\u00e6la (yfirleitt \u00feurr\u00eds), \u00eds\u00f3pr\u00f3p\u00edl alk\u00f3h\u00f3l, og einhvern klefa. \u00c6tti ekki a\u00f0 vera miki\u00f0 m\u00e1l...<\/p>\n

Svo var \u00fea\u00f0 fyrir nokkru \u00feegar \u00e9g var a\u00f0 \u00fa\u00f0a chladni-pl\u00f6tu svarta a\u00f0 \u00e9g rakst \u00e1 fl\u00f6sku me\u00f0 \u00eds\u00f3pr\u00f3p\u00edl alk\u00f3h\u00f3li og f\u00f3r a\u00f0 hugsa hvort \u00e9g \u00e6tti ekki bara a\u00f0 reyna vi\u00f0 \u00feetta. S\u00f3tti gegns\u00e6jan plastkassa og lok af frau\u00f0kassa. L\u00edmdi tusku upp \u00ed botninn \u00e1 kassanum og hellti flj\u00f3tandi k\u00f6fnunarefni \u00ed frau\u00f0kassaloki\u00f0. Lag\u00f0i svarta pl\u00f6tuna \u00e1, v\u00e6tti tuskuna me\u00f0 alk\u00f3h\u00f3linu, hvolfdi kassanum ofan \u00e1, og bei\u00f0...<\/p>\n

Flj\u00f3tandi k\u00f6fnunarefni\u00f0 ger\u00f0i \u00feetta reyndar svol\u00edti\u00f0 fl\u00f3ki\u00f0 \u00fev\u00ed \u00feegar \u00fea\u00f0 sau\u00f0 kom nokkur hreyfing \u00e1 lofti\u00f0. \u00dea\u00f0 var heldur ekki neitt svakalega gott innsigli \u00e1 milli kassans og frau\u00f0loksins svo \u00fea\u00f0 ur\u00f0u nokkur loftskipti \u00fearna \u00e1. En \u00fer\u00e1tt fyrir \u00feetta s\u00e1st greinilegt alk\u00f3h\u00f3lregn falla \u00e1 pl\u00f6tuna.<\/p>\n

En engar r\u00e1kir eftir geislavirkar agnir!<\/p>\n

\u00deri\u00f0ji kafli: \u00dea\u00f0 \u00fearf v\u00edst a\u00f0 hugsa \u00feetta a\u00f0eins...<\/h2>\n

J\u00e6ja, \u00feetta \u00fearfnast greinilega a\u00f0eins betri a\u00f0st\u00e6\u00f0na. En hverjir \u00fe\u00e1ttanna eru \u00feeir kr\u00edt\u00edsku. \u00c9g fann ekkert ganglegt \u00e1 netinu og haf\u00f0i ekki t\u00edma til a\u00f0 vasast \u00ed \u00feessu lengur.<\/p>\n

Verkefni\u00f0 bei\u00f0 \u00fev\u00ed betri t\u00edma. Reyndar endurt\u00f3k \u00e9g \u00feetta me\u00f0 \u00feurr\u00eds \u00feegar m\u00e9r \u00e1skotna\u00f0ist sm\u00e1, en \u00e9g haf\u00f0i ekki t\u00edma til a\u00f0 \u00fer\u00f3a klefann og afl\u00fasa \u00feetta a\u00f0 r\u00e1\u00f0i.<\/p>\n

Fyrir Lego forritunarkeppnina sem haldin var \u00ed H\u00e1sk\u00f3lab\u00ed\u00f3i 10. n\u00f3vember 2018. langa\u00f0i okkur hins vegar a\u00f0 sj\u00e1 hvort ekki v\u00e6ri h\u00e6gt a\u00f0 b\u00faa til svona uppstillingu, enda var \u00feema keppninnar \u201e\u00e1 sporbraut\u201c (e. into orbit).<\/p>\n

\u00c9g b\u00e6tti klefann. Fann n\u00fdja og st\u00e6rri pl\u00f6tu sem \u00e9g \u00fa\u00f0a\u00f0i l\u00edka svarta (reyndar voru g\u00f6t \u00e1 henni sem \u00e9g loka\u00f0i bara me\u00f0 l\u00edmbandi, og \u00e1 endanum lag\u00f0i svartan papp\u00edr ofan \u00e1 \u00feegar l\u00edmbandi\u00f0 losna\u00f0i vi\u00f0 k\u00e6linguna), bj\u00f3 til undirlag \u00far bylgjupappa, einangra\u00f0i me\u00f0 b\u00f3luplasti og vatnsheldi me\u00f0 sv\u00f6rtum plastpoka.<\/p>\n

Fyrir veggi og lok nota\u00f0i \u00e9g um 30 cm v\u00ed\u00f0a og 10 cm h\u00e1a s\u00edvalningslaga glersk\u00e1l \u00far IKEA og l\u00edmdi tusku \u00ed botninn \u00e1 henni. Til a\u00f0 gulltryggja mig s\u00f3tti \u00e9g nokkrar rammgeislavirkar geislalindir \u00fat \u00ed VR-I. Vopna\u00f0ur \u00feessu \u00e6tti \u00feetta ekki a\u00f0 geta klikka\u00f0.<\/p>\n

\"\"<\/a>
\u00deokuklefi me\u00f0 Cs-137 geislalnd (rau\u00f0gula sk\u00edfan) og Ra-226 geislalind (fest vi\u00f0 korktappann).<\/figcaption><\/figure>\n

\u00c9g hellti flj\u00f3tandi k\u00f6fnunarefninu \u00ed botninn eftir a\u00f0 \u00e9g haf\u00f0i lagt pl\u00f6tuna \u00e1 upph\u00e6kkun svo h\u00fan r\u00e9tt st\u00e6\u00f0i ofan vi\u00f0 k\u00f6fnunarefnispollinn, v\u00e6tti kl\u00fatinn me\u00f0 \u00eds\u00f3pr\u00f3p\u00edl alk\u00f3h\u00f3linu, lag\u00f0i geislalindirnar \u00e1 pl\u00f6tuna, hvolfdi glersk\u00e1linni ofan \u00e1, og bei\u00f0...<\/p>\n\n\n