Ticket #6773 (closed: fixed)
GetEi needs to calculate the peak in the first monitor from the data regardless of whether Ei is fixed
| Reported by: | Martyn Gigg | Owned by: | Martyn Gigg |
|---|---|---|---|
| Priority: | critical | Milestone: | Release 2.5 |
| Component: | Mantid | Keywords: | |
| Cc: | Blocked By: | ||
| Blocking: | Tester: | Andrei Savici |
Description
Currently, if Ei is fixed, then GetEi use the distance between the detectors and the given energy value to calculate where the peak in the first monitor spectrum should be. If the neutron pulse is slim, i.e high energy neutrons, then this value is close to the true value from the monitor spectrum itself and taking this as t=0.0 is a good enough approximation.
If, as is the case on LET, that the energy is much lower then the width of the neutron pulse will result in a difference between the effective time zero and that calculated from the nominal fixed ei value.
To get the correct t=0 value the time of the first monitor should always be calculated from the peak in the first monitor spectrum.
Change History
comment:2 Changed 8 years ago by Martyn Gigg
Fix GetEi2 to calculate monitor peak time from data
even for a fixed Ei. Refs #6773
Changeset: 76c69c496fe97e31a8f1dc66a840d752ff7eecee
comment:3 Changed 8 years ago by Martyn Gigg
Add a test for fixing ei. Refs #6773
Changeset: e008e2595f5eb9626df843096afb2ce745f34868
comment:4 Changed 8 years ago by Martyn Gigg
Fix GetEi2 to calculate monitor peak time from data
even for a fixed Ei. Refs #6773
Changeset: 76c69c496fe97e31a8f1dc66a840d752ff7eecee
comment:5 Changed 8 years ago by Martyn Gigg
Add a test for fixing ei. Refs #6773
Changeset: e008e2595f5eb9626df843096afb2ce745f34868
comment:6 Changed 8 years ago by Martyn Gigg
- Status changed from accepted to verify
- Resolution set to fixed
Branch: feature/feature/6773_calculate_peaktof_getei2
comment:7 Changed 8 years ago by Andrei Savici
- Status changed from verify to verifying
- Tester set to Andrei Savici
comment:8 Changed 8 years ago by Martyn Gigg
Fix GetEi2 to calculate monitor peak time from data
even for a fixed Ei. Refs #6773
Changeset: 76c69c496fe97e31a8f1dc66a840d752ff7eecee
comment:9 Changed 8 years ago by Martyn Gigg
Add a test for fixing ei. Refs #6773
Changeset: e008e2595f5eb9626df843096afb2ce745f34868
comment:10 Changed 8 years ago by Andrei Savici
- Status changed from verifying to closed
Works as described, and it does not break if you put bad workspaces for HYSPEC (it calculates t0 from the formula). However, if you do it on a bad SEQUOIA workspace (event workspace for example) it gives an error. This is going to be fixed in ticket #6782
comment:11 Changed 8 years ago by Martyn Gigg
Fix GetEi2 to calculate monitor peak time from data
even for a fixed Ei. Refs #6773
Changeset: 76c69c496fe97e31a8f1dc66a840d752ff7eecee
comment:12 Changed 8 years ago by Martyn Gigg
Add a test for fixing ei. Refs #6773
Changeset: e008e2595f5eb9626df843096afb2ce745f34868
comment:13 Changed 8 years ago by Martyn Gigg
Fix GetEi2 to calculate monitor peak time from data
even for a fixed Ei. Refs #6773
Changeset: 76c69c496fe97e31a8f1dc66a840d752ff7eecee
comment:14 Changed 8 years ago by Martyn Gigg
Add a test for fixing ei. Refs #6773
Changeset: e008e2595f5eb9626df843096afb2ce745f34868
comment:15 Changed 7 years ago by Martyn Gigg
Fix GetEi2 to calculate monitor peak time from data
even for a fixed Ei. Refs #6773
Changeset: 76c69c496fe97e31a8f1dc66a840d752ff7eecee
comment:16 Changed 7 years ago by Martyn Gigg
Add a test for fixing ei. Refs #6773
Changeset: e008e2595f5eb9626df843096afb2ce745f34868
comment:17 Changed 7 years ago by Martyn Gigg
Fix GetEi2 to calculate monitor peak time from data
even for a fixed Ei. Refs #6773
Changeset: 76c69c496fe97e31a8f1dc66a840d752ff7eecee
comment:18 Changed 7 years ago by Martyn Gigg
Add a test for fixing ei. Refs #6773
Changeset: e008e2595f5eb9626df843096afb2ce745f34868
comment:19 Changed 5 years ago by Stuart Campbell
This ticket has been transferred to github issue 7619
