To those who have your own PC:
Please access the URL below, download and install
SPECTRA before the lecture starts. If you have anyproblem, please let me know.
http://radiant.harima.riken.go.jp/spectra/index.html

Introduction to SPECTRA
Takashi TANAKARIKEN SPring-8 Center

What is SPECTRA?
• Quantitative evaluation of SR isnecessary to design optical elementsin the beamline, analyze theexperimental data, etc.
• This requires not only expertise on SR
but also numerical implementation totake into account the e-beam effects.
• SPECTRA is computer software to help
the SR users to accurately evaluate
the optical characteristics of SR fromvarious sources.

3Functions Supported• Spectrum of photon flux (density)• Spatial profile of photon flux andradiation power• K-value dependence of photon flux andradiation power• Degree of polarization (Stokesparameters)• Brilliance curve• Filtering• Coherent radiation• Fully graphical pre- and post-processor• ……
4Introduction

General Instruction (1)1. After starting the program,
open a parameter file or run[File]-[Create New].
2. GUI panels pop up to show
the parameters defining theaccelerator and light source.
3. Edit the parameters related tothe accelerator and lightsource.
4. Save the parameter file ifnecessary.

Accelerator

Light Source

5Introduction

General Instruction (2)5. Select the type of calculation (dependency and mainitem) from submenus of [Select Calculation].
6. Edit the parameters related to calculation controls.

Calculation Controls

6Introduction

General Instruction (3)7. After specifying all theparameters and selecting
options, run [Run]-[StartCalculation] command tostart a calculation.
8. Input a file name to savethe calculation results in thedialog box.
9. A progress bar pops up toindicate the status of thecalculation.

7

Introduction

General Instruction (4)10. The calculation results are saved in a file with the name you
specified and a suffix specific to the calculation type.
11. To verify the calculation results graphically, select the dataname and items to be plotted, then click “Plot”.

Plotter8

TUTORIAL
I. Spectrum
II. Modifying the Conditions
III.Spatial Profile
IV.Brilliance Curve
V. Scanning a Parameter
VI.Any Other?

9Tutorial

I. Spectrum• Calculate the partial flux of SR passing
through a rectangular slit.
• The output file of SPECTRA is an easyto-read text file. Open it with a text
editor to check the contents.
• Create a plot to visualize the outputdata.

10

Tutorial

II. Modifying the Conditions• Change the width or height of the slit tosee how it broadens the spectral profile.
• Change the position of the slit to see
how it changes the spectral profile.
• If you find any peculiar profile, increase
the accuracy level.
• Learn how to create a “calculationprocess” to do successive calculations.
• Learn how to create a “multiplot” tocompare more than one calculation
results.
11

Tutorial

III. Spatial Profile• Calculate the angular profile of thephoton flux density.
• Change the photon energy to be fixed
to see how the profile changes
according to “detuning” (energy shift).

12

Tutorial

IV. K Dependence• Calculate the flux and power as afunction of the K value. This
corresponds to the undulator gap
motion.
• Learn the difference between “Fixed”
energy and “Peak” energy.
• Add a spectrum plot to clarify themeaning of “Peak” energy calculation.

13

Tutorial

V. Scanning a Parameter• “Scanning a parameter” is an option tospecify more than one calculations witha specific parameter being changed.
• All the calculations are processed insequence.
• An animation can be created by a postprocessor.

14

Tutorial

VI. Any Other Examples?

Now, let me know yourrequests on SR computation.

15

Documentation• PDF-formatted instruction manual(spectra_reference.pdf) is placed
in “[SPECTRA]/help” directory.
• HTML-formatted help files are alsoavailable, which can be viewed byrunning the [Help]-[Help]
command.

16