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Goniometer design and crystal holders. E. Boscolo Marchi, A. Carnera, G. Della Mea, D. De Salvador R. Milan, A. Sambo, C. Scian, A. Vomiero. Outline. Requirements of goniometer system Goniometer design Capabilities of the goniometer system Suggestions for experimental layout Open questions. - PowerPoint PPT Presentation
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Crystal Channeling Workshop Geneva 9th - 10th March 2006
Goniometer design and crystal holdersGoniometer design and crystal holders
E. Boscolo Marchi,E. Boscolo Marchi, A. Carnera, G. Della Mea, D. De SalvadorA. Carnera, G. Della Mea, D. De SalvadorR. Milan, A. Sambo, C. Scian, R. Milan, A. Sambo, C. Scian, A. VomieroA. Vomiero
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
OutlineOutline
• Requirements of goniometer system
• Goniometer design
• Capabilities of the goniometer system
• Suggestions for experimental layout
• Open questions
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Requirements of goniometer system
• Sub -radiant steps / wide range angular scanning
• Top resolution / accuracy / repeatability
• Versatility for mounting differently shaped crystal holders / crystals
• 2 angular degrees of freedom
• 2 translations
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Rotary stageRotary stage
Goniometer stageGoniometer stageLinear stageLinear stage
Crystal holderCrystal holder
Goniometer designGoniometer design
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
First rotary stage (First rotary stage (yy-rotation)-rotation)
Beam directionBeam direction
x
z
y
Top view
BeamBeam
Top view
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Technical data of Technical data of yy-rotary stages-rotary stages
Full range Full range 360°360°
Resolution ~Resolution ~ 0.35 0.35 radrad 0.7 0.7 radrad
Accuracy ~ Accuracy ~ 10 10 radrad 105 105 radrad
Repeatability < 5 Repeatability < 5 radrad 0.7 0.7 radrad
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Cradle-likeCradle-like second rotary stage (second rotary stage (xx-rotation)-rotation)
Beam directionBeam direction
x
z
y
Lateral view
BeamBeam
Lateral view
xx--yy intersection intersection
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Technical data of the cradle-like rotary stageTechnical data of the cradle-like rotary stage
Full rangeFull range 20°20° 10°10°
Resolution ~Resolution ~ 0.065 0.065 rad rad 1 1 radrad
Accuracy ~ Accuracy ~ 10 10 radrad 175175radrad
Repetibility ~ Repetibility ~ 0.5 0.5 rad rad 1 1 radrad
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Linear stageLinear stage
Beam directionBeam direction
x
z
y
Linear axis in x Linear axis in x directiondirection
Alignement of the Alignement of the crystal with the crystal with the
positioning systempositioning system
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Technical data of the linear stage
• Full range 25 - 150 mm
• Resolution ~ 0.5 m
• Accuracy ~ 5 m
• Repeatability ~ 0.5 m
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Vertical (E853)
Horizontal (RD22)
Crystal insertion
Up-downUp-down
SideSide
Crystal positioning and beam deflectionCrystal positioning and beam deflection
Beam size: is Beam size: is beam available?beam available?Can we directly detect volume Can we directly detect volume reflection?reflection?
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Beam shape / crystal size and “septum width”
The most effective The most effective geometry for reducing geometry for reducing “septum width” effect“septum width” effect
““Septum width” (Biryukov 1995Septum width” (Biryukov 1995, Elsener 1996, Carrigan 2002) Elsener 1996, Carrigan 2002)
effect highly reduced by “etching effect highly reduced by “etching strategy” proposed by Ferrarastrategy” proposed by Ferrara
Crystalline perfection: low-Crystalline perfection: low-energy Rutherford energy Rutherford
backscattering channeling backscattering channeling (Baricordi 2005) (Baricordi 2005)
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Alignment system (Laser-based, see Elsener 1996)
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
x
z
yBeamBeam
Solution for two crystal holdersSolution for two crystal holders
B A
(courtesy Y. Ivanov)(courtesy Y. Ivanov)
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
BeamBeamTop viewTop view
AB
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
BeamBeamTop viewTop view
AB
50 50 mmmm
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
BeamBeamTop viewTop view
AB
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
BeamBeamTop viewTop view
A B
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
BeamBeamTop viewTop view
A B
10 10 mmmm
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
Calendar
• Goniometer design next week
• Alignment system design 1st week April
• Software for motor control end of April
• Alignment system set-up @LNL May
• Goniometer set-up and test @ LNL May
Crystal Channeling WorkshopCrystal Channeling Workshop
Geneva 9Geneva 9thth - 10 - 10thth March 2006 March 2006
List of the points of detail to be discussed
• mechanical mounting of crystal holders on the goniometer (holders suppliers)
• simultaneous mounting of two crystals: technically possible, lower versatility, unadvisable from our point of view (all)
• movement across the beam (H8)
• preliminary off-line alignment of the crystal and design of alignment system (H8 and crystals suppliers)
• beam position and on-line crystal alignment (H8 and beam detection)
• cabling the remotely controlled motors (H8)
