$$\renewcommand\AA{\unicode{x212B}}$$

# ConvertToYSpace v1¶

## Summary¶

Converts workspace in units of TOF to Y-space as defined in Compton scattering field

## Properties¶

Name

Direction

Type

Default

Description

InputWorkspace

Input

MatrixWorkspace

Mandatory

The input workspace in Time of Flight

Mass

Input

number

Mandatory

The mass defining the recoil peak in AMU

OutputWorkspace

Output

MatrixWorkspace

Mandatory

The output workspace in y-Space

QWorkspace

Output

MatrixWorkspace

The output workspace in q-Space

## Description¶

The final unit of the x-axis is changed to momentum (Y) space as defined by the formula:

$$Y = 0.2393\frac{M}{\epsilon_i^{0.1}}(\omega - \frac{q^2}{2M})$$

where $$M$$ is the mass in atomic mass units, $$\displaystyle\epsilon$$ is the incident energy, $$\displaystyle\omega$$ is the energy change and $$q$$ is defined as $$\sqrt{(k_0^2 + k_1^2 - 2k_0k_1\cos(\theta))}$$.

The TOF is used to calculate $$\displaystyle\epsilon_i$$ and the $$\displaystyle1/\epsilon$$ dependence causes an increasing set of TOF values to be mapped to a decreasing set of $$\displaystyle Y$$ values. As a result the final $$Y$$-space values are reversed to give a workspace with monotonically increasing $$Y$$ values.

## Usage¶

Example - simple convert to Y-space:

###### Simulates Load workspace for and Indirect spectrometer #################
tof_ws = CreateSimulationWorkspace(Instrument='MAR',BinParams=[-50,2,50],UnitX='TOF')
SetInstrumentParameter(tof_ws,ParameterName='t0',ParameterType='Number',Value='0.5')
SetInstrumentParameter(tof_ws,ParameterName='efixed',ParameterType='Number',Value='30.')
###### Convert data to format acceptable by ConvertToYSpace
tof_ws = ConvertToPointData(tof_ws)
###### Convert to Y Space
wsY=ConvertToYSpace(InputWorkspace='tof_ws',Mass='30')
#
# Look at sample results:
print('part of the converted workspace:')


Output:

part of the converted workspace:
218.179247674 4.44978825566 0.0
217.970903402 4.44292943299 0.0
217.763039952 4.43608530232 0.0
217.555655487 4.42925581439 0.0
217.348748180 4.42244092015 0.0
217.142316213 4.41564057078 0.0
216.936357776 4.40885471770 0.0
216.730871069 4.40208331255 0.0
216.525854298 4.39532630718 0.0
216.321305680 4.38858365367 0.0


Categories: AlgorithmIndex | Transforms\Units