Characteristics
| ILL7 building, Cold neutron guide H16 |
|---|
| (Vertical Cold Source) |
| Monochromatisation | |
|---|---|
| 6 counter-rotating choppers | |
| Chopper velocity Vo (revolution per minute) | 2000 rpm to 17000 rpm |
| Incident wavelength λo | 1.8 Å to 20 Å |
| Sample | |
|---|---|
| elastic energy resolution at 5.0 Å, 8500rpm | ~ 100 µeV |
| max neutron energy loss | hωmax 0.6×Eo Emin ≈ 0.4×Eo (λmax = 1.5λo) |
| max neutron energy gain | Emax ~ ∞ . . . |
| max momentum transfer Qmax | 11.48/λo Å-1 |
| horizontal divergence (no collim.) | ~ 0.1×2×λo [°] |
| vertical divergence (no collim.) | ~ 0.1×3×λo [°] |
| Collimation before sample | - / 30' / 60' |
| beam size at the sample | ~ 15×50 mm\(^{2}\) |
| flux at the sample at 5.0 Å | 6.83×105 [n/cm2/s] |
| Detectors | |
|---|---|
| detector shape | cylindrical |
| detector surface [m2] | 30.0 |
| fight path (radius of reading) [m] | 4.0 |
| effective detection height [m] | 3.0 |
| scattering angular range [°] | -12° to 135° |
| vertical angular range [°]e | ±20.55° |
| solid angle covered | 1.8 sr (~0.6π) |
| min. & max. momentum transfer [Å-1] | 0.2/λ [Å] - 11.8/λ [Å] |
| spatial resolution [cm2] | 2.6 x 2.6 |
| angular resolution [° / rad / '] | 0.37° / 6.10-3rad / 22 |
| detector type | position sensitive \(^{3}\)He counters |
| gas mixture | 4.75 bar \(^{3}\)He +1.25 bar CF4 |
| detector efficiency | ~ 80% for Eo = 3.27 meV (5 Å) |
| dead time / max. count rate (per tube) | ≤ 10 µs / ≥ 100 kHz |
| material | stainless steel |
| number of detectors units (32 tubes/unit) | 12 |
| tubes diameters [inches/cm] | 1' / 2.54 |
| Acquisition | |
|---|---|
| nb. of pixels per tube / per unit / total | 256 / 8192 / ~105 |
| time channel / pixel | ≤ 1024 |
| max. raw data volume / spectrum | ≤ 768 Mb |
| Sample environment | |
|---|---|
| accommodating samples with 69 mm Ø | |
| dilution fridge (LT1) | ≤ 50mK ... 1.6K |
| vertical cryomagnet S(MV) | 0 ... 2.5 Tesla and 0 ... 10 Tesla |
| ILL orange cryostat (CO) | 1.5 ... 310 K |
| cryofurnace (CF) | 2.5 ... 600 K |
| furnace (F2) | 300 ... 1600 °C |
| heating and cooling loop (CL) | 100 ... 620 K |
Instrument description
IN5 is a general purpose direct geometry Time of Flight (ToF) spectrometer. It is used to study low-energy transfer processes as a function of momentum transfer. Typically this instrument is used for measurements in the small energy and momentum transfer region with values of the order of δE/E = 1 % for the energy resolution (e.g. quasi-elastic scattering in solids, liquids, molecular crystals and inelastic scattering with small energy transfers in the order of magnitude 0.1 - 250 meV). It offers total flexibility of wavelength selection and chopper speed which permits considerable optimisation of the energy range, energy resolution, momentum-transfer range and countrate.
Primary spectrometer:
the chopper system provides an extremely well defined resolution function which remains nearly gaussian (counter-rotating disks) down to 1/10 000 of its height.
Secondary spectrometer:
it consists in an large cylindrical array of pixelated position sensitive detector (PSD) mounted inside a vacuum time-of-flight chamber 4m from the sample. PSDs cover a large gapless detection surface (30m2) with a spatial resolution comparable to triple-axis instruments. With the new detector, the instrument has a large solid-angle for powder and amorphous systems experiments and is fully equipped for single-crystal spectroscopy.
Sample area:
a large sample chamber (max diameter = 80cm, depth ~ 130cm) allows hosting the broad range of IN5 sample environments but also user-designed equipments (contact instrument responsibles before). The non-magnetic material surrounding the sample allows the use of either high magnetic field (limited to 2.5T at the moment it is foreseen to purchase a specific magnet for higher fields - equal or above 10T) or neutron polarisation devices (still to come).