Hi Carmen,

Here is a simple example with 2 spheres (attached to my reply):

The code is as follows:

# Clear all detectors
clear = NSDD(1, 0, 0, 0)

# Run a raytrace
NSTR 1, 0, 0, 0, 0, 1, 0

# Read power of all objects between the first and last
# object (defined below)

# First object
first_object = 2

# Last object
last_object = 3

# Specify PRINT output file
OUTPUT "test.txt"

# Loop over the detectors
FOR object, first_object, last_object, 1
	# Record total flux of current object
	flux = NSDD(1, object, 0, 0)

	# Print flux to file specified by OUTPUT
	PRINT flux
NEXT

Please note the following about the OUTPUT keyword:

If a valid filename is provided, then subsequent PRINT commands will output to the filename specified. If a filename with no path is provided, output will be directed to the <data>\Macros folder.

The result gives the following values:

0.1954
0.8046

And these are the text tab of the detector viewers:

Sphere 2, NSCG Surface 1: 
Number of pixels: 4512, Total Hits = 19543

Peak Power      : 1.0460E-02 Watts
Total Power     : 1.9543E-01 Watts

Sphere 3, NSCG Surface 1: 
Number of pixels: 4512, Total Hits = 80457

Peak Power      : 1.0500E-02 Watts
Total Power     : 8.0457E-01 Watts

Let me know if you have any other question.

Take care,

David