ENTRY            B0092   20011220
SUBENT        B0092001   20011220                                 
BIB                  8         43                                 
TITLE      B-10 and B-11 Production Cross Sections in C-12        
           Spallation by Protons and Alpha Particles.             
           Application to Cosmic Ray Propagation                  
AUTHOR     (P.FONTES)                                             
INSTITUTE  (2FR PAR) Laboratoire Rene Bernas                      
REFERENCE  (J,PR/C,15,2159,1977)                                  
SAMPLE     Stacks Consisting of High Purity Graphite Sheets,      
           Thickness 1 and/or 0.2 mm, Containing Less Than 5 Ppb  
           Of Natural Boron. The Number and the Thickness of the  
           Sheets Used For an Experiment Depended on the Energy   
           Of the Incident Particles. Due to the Small Energy Loss
           In the Individual Foils the Stack was Obviously not    
           Used For Energy Degradation But Rather For Production  
           Of Several Targets Per Run.                            
METHOD     (INTB,SITA,ASEP)                                       
           After Irradiation One Graphite Sheet Per Analysis was  
           Burnt on a Small Au-Disk on Which Most of Spallation   
           Products Remained After Total Combustion. Combustion   
           Was Performed at Temperatures Below 700 Centigrades,   
           Where Escape of Volatile Boron Compounds was Checked   
           To be Small (LESS THAN 5% UNCERTAINTY IN THE CROSS     
           SECTIONS).                                             
           In All Cases B-11/B-10 Ratios were Measured by Means   
           Of a Mass Separator. The Boron Ionization Efficiency   
           Relative to That of be was Strongly Increased by       
           Deposit of About 1 Mg of High Purity Water on the      
           Combustion Residue.                                    
           Data were Corrected For Isotopic Discrimination of the 
           Mass Separator Which was Determined Using a Standard   
           Boric Acid Sample.                                     
           The Natural Boron Content of the Targets was Determined
           From Blank Graphite Sheets.                            
ERR-ANALYS (DATA-ERR) The Errors Given For the Ratios and the Data
           Are Standard Errors Coming from Mass Peak Ratio        
           Measurement and from Determination of the              
           Discrimination Factor of the Spectrometer.  Included   
           Are the Uncertainties of the Monitor Cross Sections.   
           (MONIT-ERR). Any Information is Absent.                
HISTORY    (19781213C)Lakw                                        
           (19940711A) Some Corrections have Been Included by     
            CAJAD                                                 
           (19980610A) Lower Case. Monitor is Corrected.          
           (20011010U) Last checking has been done.               
ENDBIB              43                                            
NOCOMMON                                                          
ENDSUBENT           46