program to make calibrations based on relativistic kinematics and SRIM data for charged particle losses in material

.L nrfit.C+
nrfit("calib.txt")

The data are in a text configuration file - e.g. calib.txt

Syntax:

line starting with # is a comment BUT line starting with #define or #free contains a definition

the main part has the structure

# k    dk           reaction     medium    Exc   Tbeam thickness angle   deadlay livelay P3  P2  P1   P0
#------------------------------------------------------------------------------------------

• k and dk ... are channel and error

• reaction ... the notation is lowercase elementA where the A is a mass number ... the reaction is described by a word projetile_target_ejectile_remnant ... isotopes must correspond to data prepared from SRIM and to internal mass tables in the source code

• medium ... material of the target ... must correspond to data prepared from SRIM

• Exc. ... excited state in MeV ... influences kinematics

• Tbeam ... kinetic Energy of the projectile

• thickness ... in microns

• angle ... beam deviation angle

• deadlay ... dead layer of the detector

• livelay ... detector thickness

• P3-P0 ... polynomial calibration coefficients highest to lowest order

#########################
# alfa T1  dE
 872.593    0.047  he4_he4_he4_he4  mylar  0.0    T4     0.0  0.0   de1layau  de1laysi    0.0 0.0 pde1_1 pde1_0
 879.290    0.025  he4_he4_he4_he4  mylar  0.0    T3     0.0  0.0   de1layau  de1laysi    0.0 0.0 pde1_1 pde1_0
 921.394    0.057  he4_he4_he4_he4  mylar  0.0    T2     0.0  0.0   de1layau  de1laysi    0.0 0.0 pde1_1 pde1_0
 927.968    0.025  he4_he4_he4_he4  mylar  0.0    T1     0.0  0.0   de1layau  de1laysi    0.0 0.0 pde1_1 pde1_0

the configuration can have variables and eventualy free for fit:

#--------------T7--------------
#     40ug
#define var  de7layau=0.02070
#define var  de7laysi=264
#define var  pde7_1=0.006372
#define var  pde7_0=-0.107064
#   BEAM  FROM  MONO  16.18
#define var T=16.42
############################
#free var T=step=0.01
#free var pde1_1=step=0.0001
#free var pde1_0=step=0.0001

An example of the result:

• Use energy in MeV
• different linear calibration coefficients ... data is shown with different color?

• file can have directives define, var, include

define var T1=5.8038   
free var T=step=0.01  
include= two.txt

• equal sign = is also used to easily tokenize

• input format till 2015

chan  dchan  reaction_a_b_c_d_k12 tgtmaterial excitation Ebeam tgtthick Rangle layerAu layerSi 0.0 0.0  slope offset

• passing through Au and Al passive layers 20nm and 100nm is important for 3he at low energies, not for deuteron at 15MeV

• Energy for thick detector: I cannot fit solely E, FWHM and thus a position is determined by losses in dE. The only way is to fit (dE+E).

• a correct verticality compensation factor should bring a linear dependence.