Analysis report4. 13th. Friday 2007.
H.Yim
To apply efficiency correction on the data spectrum, DEMONS code is investigated and modified.
Kinetic energy vs. Energy Loss(Before ADC conversion)
Kine
tic e
nerg
y [M
eV]
Energy Loss [MeV]
Kine
tic e
nerg
y [M
eV]
Energy Loss [MeV]
Kine
tic e
nerg
y [M
eV]
Overlaid
DEMONS GEANT
Energy Loss [MeV]
E-loss distribution is same with GEANT.
Then, response function is ?
Modified DEMONSOriginal response function Birk’s saturaion function
Kine
tic E
nerg
y [M
eV]
ADC [MeVee]
Kine
tic E
nerg
y [M
eV]
Overlaid with GEANT result
DEMONS
ADC [MeVee]
Birk’s saturation function is successfully implemented in DEMONS code.
Measurement of Birk’s parameter
C1=0.00757
Birk’s saturation function
Original parameter
Measured parameter
~67 ~60.3
ADC[MeVee]ADC[MeVee]
Kine
tic E
[MeV
]
ADC[MeVee] ADC[MeVee]
Kine
tic E
[MeV
] DATA (E549) GEANT
Applying measured Birk’s parameters to simulations
GEANT with new Birk’s paraDEMONS with new Birk’s para
Kine
tic E
nerg
y [M
eV]
ADC [MeVee]
Kine
tic E
nerg
y [M
eV]
ADC [MeVee]
Kine
tic E
nerg
y [M
eV]
ADC [MeVee]
Overlaid
Now, DEMONS and GEANT shows same performance.
(at least, about proton simulation)
Data(E549) & GEANT
Kine
tic e
nerg
y [M
eV]
ADC [MeVee]
Kine
tic e
nerg
y [M
eV]
ADC [MeVee]
Kine
tic e
nerg
y [M
eV]
Overlaid
DEMONS GEANT with new Birk’s para
ADC [MeVee]
Neutron spectrum comparison
ADC [MeVee]ADC [MeVee]
1/
beta
1/
beta
Modified DEMONS Data (E549)
1/beta vs. ADC 1/beta vs. ADC
Now, stripe pattern is well agree.
Neutron efficiency
Momentum MeV/c
Dete
ctio
n e
ffici
ency
10 MeVee
15 MeVee
7 MeVee
5 MeVee
3 MeVee
0 MeVee
20 MeVee
Threshold
Background subtracted spectrum
Semi-inclusive [Line] and background [Point]
Momentum [MeV/c] Momentum [MeV/c] Momentum [MeV/c] Momentum [MeV/c] Momentum [MeV/c]
Momentum [MeV/c] Momentum [MeV/c] Momentum [MeV/c] Momentum [MeV/c] Momentum [MeV/c]
Background subtracted neutron spectra
5 MeVee 7 MeVee 10 MeVee 15 MeVee 20 MeVee
5 MeVee 7 MeVee 10 MeVee 15 MeVee 20 MeVee
Efficiency corrected spectra
Efficiency corrected
Background subtracted
Semi-inclusive
Momentum [MeV/c] Momentum [MeV/c] Momentum [MeV/c]
Summary
• Response function of DEMONS code is modified to make agreement with data.
• Efficiency corrected neutron spectra were obtained.
