instrument specs

About PEARL

A description of PEARL is published in the Journal of Applied Crystallography:


Design and performance of a novel neutron powder diffractometer: PEARL at TU Delft
 
L. van Eijck, L. D. Cussen, G. J. Sykora, E. M. Schooneveld, N. J. Rhodes, A. A. van Well and C. Pappas
 
J. Appl. Cryst (2016). 49
 
doi:10.1107/S160057671601089X

 

The instrument, in graphs

The PEARL calibration data for the 1.67AA (533) setting at room temperature. This data was measured for 1 hour on 1.22gr of NIST sapphire.
The PEARL calibration data for the 1.67AA (533) setting at room temperature. This data was measured for 1 hour on 1.22gr of NIST sapphire.

The instrumental contribution to the peak widths as a function of scattering angle, for the 1.67AA (533) setting of PEARL. The resulting minimum resolution in d-spacing is δd / d 1.5e-3.
The instrumental contribution to the peak widths as a function of scattering angle, for the 1.67AA (533) setting of PEARL. The resulting minimum resolution in d-spacing is δd / d= 1.5e-3.

sample cans

The volume of approximately 1.4 cm3 (diameter 6mm and 50mm length) of the sample can defines the amount of sample needed for neutron diffraction.
The volume of approximately 1.4 cm^3 (diameter 6mm and 50mm length) of the sample can defines the amount of sample needed for neutron diffraction.

sample cans 0.15mm wall thickness:

outer diameter vanadium tube:

  • 6.35mm
  • 7.90mm
  • 9.55mm

length vanadium tube from bottom of TiV flange:

  • 47.00mm
  • 59.55mm
  • 59.55mm

TiV flange:

outer diameter: between 21.2mm and 21.6mm

thickness: 5mm

Aluminium closing lid / flange:

outer diameter: between 21.2mm and 21.6mm

thickness: 5mm

female M4 connection approx 4mm deep.

Screws to close the Alu lid on the TiV flange:

4x M1.6 x 10mm (Alan key head 2.95mm outer diameter; head height 1.5mm)

rubber o-ring:

13×1 viton

 
approximate volumes of these 6mm, 8mm and 9mm diameter cans:

V (6mm) = 3mm**2 * pi * 50mm = 1413 mm3
V (8mm) = 4mm**2 * pi * 60mm = 3015 mm3
V (9mm) = 4.5mm**2 *pi * 60mm = 3817 mm3

m (6mm): can=7.95, lid=4.83, viton o-ring=0.07, bolt=0.17, 4*bolts=0.67, TOTAL=13.53 gr
m (8mm): can=7.73, lid=4.93, viton o-ring=0.07, bolt=0.17, 4*bolts=0.67, TOTAL=13.40 gr

(flange of 8mm weighs less than that of 6mm)

Temperature control: Cryostat and Heater

A cryostat with vanadium tail (VTI) will be available soon. It currently covers 80K – 300K and we expect to reach 2K soon.

A sample heater allow for temperature control from 300K to 800K.

Data treatment

A python module can be found on github that can be used to read data and do basic operations in preparation for Rietveld refinement. The module is regularly updated, so “follow us” at https://github.com/LambertVanEijck/pearl .