Derivation of energy calibration constants

The mapping from $N_{eff}$ to energy is derived from Monte-Carlos of mono-energetic electrons at the detector center. To derive this map we must first determine the absolute detector gain by comparing $^{16}$N data with a Monte-Carlo calculation. We can then generate monoenergetic electrons with this calibrated Monte-Carlo to generate the energy $\longrightarrow$  $N_{eff}$ map used by RSP.

The script rsp_calibrate.scr can be used with RSP to generate the energy calibration constants for a specific fitter and optical constants. The header of the script should be edited to reflect the $^{16}$N data and fitter to be used:

#!/usr/bin/perl
#rsp_calibrate.scr: Generate energy calibration constants
#Modify the following as required

$fitter = "ftt";
$fitidx = 5;
$n16_input = "FILE INP 1 /prod/data/SNO_0000010429_000.zdab";

The file rsp_ntuple.dat should also be modified to reflect the desired fitter.

The script should then be executed. It will generate SNOMAN command files and

• Process the $^{16}$N run and determine the mean of the $N_{eff}$ distribution
• Perform a Monte-Carlo calculation for the $^{16}$N source and determine the mean of the $N_{eff}$ distribution
• Calculate the PMT collection efficiency to scale the Monte-Carlo to the data
• Generate a set of mono-energetic electron Monte-Carlo's and generate the new energy calibration constants.

The new calibration constans will be written the file new_energy_calibration.dat. The script will also generate the following figures and files:

• set_coll_eff.cmd - SNOMAN command file to set the collection efficiency
• rsp_scale.ps - comparison of $^{16}$N data and Monte-Carlo
• rsp_neff.ps - neff distributions for monoenergetic electrons

Figure 19.1: $N_{eff}$ distributions for $^{16}$N generated with rsp_calibrate.scr

Figure 19.2: $N_{eff}$ distributions for electrons generated with rsp_calibrate.scr