On Thursday 11th October 2018 we have produced and measured the very first TOF MIEZE signal on LARMOR!
With this MIEZE mode it is possible to measure dynamics in a sample (0.1ns -10ns). This mode gave us great challenges during the design phase as it was very demanding on the electronics of LARMOR instrument. It was truly very exciting to finally see the very first modulations on our screen appear (left).
First arm converted to a MIEZE arm
First MIEZE signal with 413 KHz modulation
On the right one can see the the fist arm of the LARMOR instrument that for this occasion is converted into a MIEZE configuration with two Vcoils and two RF flippers running at different frequencies. The highest MIEZE modulation frequency reached and measured was 1.03 MHz!
In only 4 days (and nights) we have completely commissioned the MIEZE mode!
The two MIEZE detectors, the blue is from FRM2 and the Al in front is from ISIS
This demanding schedule was only possible due to a good preparation of Niels Geerits who completed his Master project in Delft building a copy of the instrument and gaining months of experience. This together with the great help and expertise of Cristian Franz, who is the MIEZE expert at RESEDA at the FRM2 in Munich. He also brought a essential piece of kit, a very fast detector, see right (blue), that is able the measure the very fast modulation signals (up to 1 MHz) in TOF. An alternative fast detector was made available by Davide Raspino from ISIS that also appeared very imported for the success of the experiment. Summarize, it was a great team effort of ISIS, our FRM2 collaboration and Delft that made everything come together and produce an excellent commissioning experiment.
The collaboration between TU Delft and ISIS has recently delivered a new high angle bank for Larmor which has now been used for the first time June 2018. The Figures below show preliminary results of a simultaneous SANS and diffraction study of in-situ precipitate growth that is coupled to the phase transformation kinetics in steel (by the group of Erik Offerman TU-Delft).
. time resolved SANS time resolved Diffraction
We proudly pinned a new picture to the door of the measuring cabin of LARMOR. The top (circular) plot is a SANS pattern that is the basic mode of operation of the instrument.
Since 19-02-2017 we added a so called “Atari plot” to the functionality of LARMOR. This is a spin-echo phase plot as function of wavelength. The central horizontal stripe represents the constant echo phase for all wavelengths, which looks quite good!
Quality of the data is as expected, we can now officially say, SESANS is a operational mode of LARMOR!
Installation of all components on the LARMOR beam line on the 3rd of February 2017. Now these components, developed in Delft, found there final destination in the LARMOR blockhouse. Now the commissioning and debugging can start!
Below we have the team that did the job. Taking it from ideas trough sketches, prototypes, models, more prototypes, testing, final design, construction and finally installation. A long but rewarding process.
We are currently working on finalising the first arm in Delft. This will be shipped and installed end of august at ISIS.
For the final test in Delft the magnets are put on the rails, the cables get disentangled and cut to length, all the power supplies and other electronic devices are given their own spot under the table, the guide field coils get installed, … And of course the software for the motion is being tested rigorously. When this is all done we will pack everything and ship it to ISIS for the final installation .
LARMOR is a neutron scattering instrument that is now partially financed by a "NWO groot" grant and is been built at the UK neutron source ISIS. The basis is a competitive future proof SANS instrument fully paid, developed and run by ISIS. The Dutch contribution will significantly increase its functionality by exploiting a broad range of Larmor labeling methods in the space and time domain.