Sur­face en­gi­nee­ring and ad­van­ced coa­tings for the next ge­nera­ti­on of X-ray dif­frac­ti­ve op­tics - XOP­TICS

Pro­ject sum­ma­ry

The pro­po­sed pro­ject is aimed to de­ve­lop and fur­ther re­fi­ne cru­cial fa­bri­ca­ti­on steps of high-​end X-ray dif­frac­tion op­tics. The no­wa­days X-ray op­tics has to ful­fill very tight spe­ci­fi­ca­ti­ons re­gar­ding the sur­face fi­nish, sur­face rough­ness and sub-​surface crys­tal qua­li­ty. The sur­face fi­gu­re has to be bet­ter than lamb­da/20 me­a­su­red by re­flec­ted wave dis­tor­ti­on at HeNe laser wa­velength. The sur­face rough­ness has to be lower than 0.1 nm RMS. And the sub-​surface da­ma­ge (SSD) to the crys­tal lat­ti­ce in­tro­du­ced by sur­face ma­nu­fac­tu­ring tech­ni­que has to be re­mo­ved. The con­ven­tio­nal sur­face cut­ting, mil­ling, grin­ding, lap­ping and po­li­shing tech­ni­ques are sui­ta­ble only for pla­nar or sym­metric sur­faces. How­e­ver the la­test de­ve­lo­p­ments in the X-ray dif­frac­tion op­tics in­vol­ve fa­bri­ca­ti­on of com­pli­ca­ted sym­metric and asym­metric channel-​cuts where the ac­ti­ve sur­faces are not ac­ces­si­ble by con­ven­tio­nal sur­face ma­nu­fac­tu­ring and po­li­shing tech­ni­ques. In the last thir­ty years the ultra-​precision ma­nu­fac­tu­ring using dia­mond tools was es­tab­lished as a pro­mi­sing ma­nu­fac­tu­ring tech­ni­que. This tech­ni­que coined as sin­gle point dia­mond tur­ning (SPDT) can ma­nu­fac­tu­re pre­ci­se in­ter­faces with very low fi­gu­re error and sur­face rough­ness less than 1 nm RMS. This pro­ject tar­gets the re­fi­ne­ment of SPDT ma­nu­fac­tu­ring tech­ni­que in­ten­ding to reach the lo­west pos­si­ble SSD. The ma­nu­fac­tu­ring op­ti­miza­ti­on cy­cles will be sup­por­ted by me­a­su­re­ments and nu­me­ri­cal si­mu­la­ti­ons of re­si­du­al stress in­tro­du­ced by SPDT. In order to make the SPDT com­pa­ti­ble with the fa­bri­ca­ti­on of the la­test high-​end X-ray op­tics ad­di­tio­nal po­li­shing steps has to be de­ve­lo­ped es­pe­cial­ly for the nested sur­faces. The aim of this pro­ject is to re­fi­ne the exis­ting po­li­shing tech­ni­ques in com­bi­na­ti­on with SPDT. A spe­cial goal is the de­ve­lo­p­ment of new po­li­shing ap­proa­ches. Es­pe­cial­ly we will ad­dress the com­bi­na­ti­on of SPDT ma­nu­fac­tu­ring with ion beam po­li­shing and na­no­se­cond laser re­mel­ting tech­no­lo­gies. Fur­ther­mo­re we will de­ve­lop wear and oxi­da­ti­on re­sistant func­tio­nal coa­tings that will sup­press X-ray scat­te­ring at low in­ci­dence/exit an­gles.