**10. Configurations of the PGNAA facility**

In the progress of using PGNAA method for medical purposes many kind of setups and configurations suggested and applied. In the following some of them have been shown Figure 5 is a schematic of a conventional machine used to measure the body composition. Another gold design is shown in figure 6. In this setup the uniform neutron flux will meet the patient tissue so we can get good results.

Figure 7 shows a cross-sectional view of the modified BCCA. Sheets of 2 cm thickness of Lead surround the neutron moderator (here paraffin wax) to provide radiation shielding for personnel. To protect personnel from biological effects of neutrons and to reduce background counts, neutron shielding must be considered. Since high-speed neutrons are more difficult to shield, at first neutrons must be moderated by a hydrogenous material such as paraffin wax (14.86 % H, 85.14 % C). Because of Hydrogen has a great absorption Cross Section for thermal neutrons, the risk of neutrons for personnel vanishes. One of the benefits that the moderator has been covered with a 2cm layer of Pb is that the gamma-rays (2.224 MeV) produced by the H(n, γ) interaction are filtered.

A sphere of Lead has been centered at the source position to filter gamma-rays of the neutron source. Another part of this configuration is an invert, rectangular, cuneus void cast within the paraffin wax block ( 40 50 60 *cm cm cm* × × ). To protect patient body from high-rate

A third problem associated with prompt-gamma neutron activation analysis is the high count rate encountered. Since the output pulse from a detector is of a finite length (typically with a rise time of 0.25 \_s and a fall time of up to 10 \_s), any radiations being detected within this interval may be added to the original event, producing a pulse of greater amplitude. This process of random summing at high count rates has the effect of increasing the background in the gamma ray spectrum further. The statistical uncertainties in the determination of the abundance of any element in the body from the number of events in the corresponding full-energy peak in the spectrum are increased by the contribution from the underlying background. It is necessary to minimize this background. One method to reduce the random summing background to nitrogen is to electronically suppress the counting of events below 5 MeV for the major part of the measurement, and only count the

whole spectrum (including the 2.223 MeV peak from hydrogen) for a short interval .

are preferred.

be measured.

**10. Configurations of the PGNAA facility** 

the patient tissue so we can get good results.

(2.224 MeV) produced by the H(n,

This increases the nitrogen signal to background by 18%. Since many (inelastic or non-elastic scattering) reactions (e.g. with carbon, oxygen) have an energy threshold of several megaelectron-volts, the optimum signal for a given dose is achieved when the subject is irradiated with monoenergetic neutrons at 14.4 MeV from a D–T neutron generator. These neutron generators, or alternatively cyclotrons, can be temperamental to operate, so that often neutron sources, comprising an alloy of beryllium and an alpha emitting radionuclide,

These sources (241Am/Be, 238Pu/Be) produce a 4.439 MeV gamma ray per neutron which may interfere with the determination of carbon and add significantly to the problem of

Moreover, it is possible to improve the signal to background ratio in operating a neutron generator or cyclotron in a pulsed or cycled mode by counting short-lived induced activity between pulses of neutrons, thereby reducing the lower limit of the target element that can

In the progress of using PGNAA method for medical purposes many kind of setups and configurations suggested and applied. In the following some of them have been shown Figure 5 is a schematic of a conventional machine used to measure the body composition. Another gold design is shown in figure 6. In this setup the uniform neutron flux will meet

Figure 7 shows a cross-sectional view of the modified BCCA. Sheets of 2 cm thickness of Lead surround the neutron moderator (here paraffin wax) to provide radiation shielding for personnel. To protect personnel from biological effects of neutrons and to reduce background counts, neutron shielding must be considered. Since high-speed neutrons are more difficult to shield, at first neutrons must be moderated by a hydrogenous material such as paraffin wax (14.86 % H, 85.14 % C). Because of Hydrogen has a great absorption Cross Section for thermal neutrons, the risk of neutrons for personnel vanishes. One of the benefits that the moderator has been covered with a 2cm layer of Pb is that the gamma-rays

 ) interaction are filtered. A sphere of Lead has been centered at the source position to filter gamma-rays of the neutron source. Another part of this configuration is an invert, rectangular, cuneus void cast within the paraffin wax block ( 40 50 60 *cm cm cm* × × ). To protect patient body from high-rate

γ

random summing of gamma rays in the detectors unless the source is well shielded.

2.224 MeV gamma-rays, the inner wall of the valley, made above the neutron source (Figure 7), was lined by Pb sheet of 2cm thickness. By this way, a rectangular neutron-beam aperture measuring 40 cm length (perpendicular to the paper sheet) and 20 cm (width) at the sample location is defined.

Fig. 4. A typical schematic representation of PGNAA setup based accelerator. In this setup the D2O is used as moderator.

Fig. 5. Schematic of a conventional machine used to measure the Total Body Nitrogen (TBN)

Body Composition Analyzer Based on PGNAA Method 323

The authors are attempting to investigate all the aspects related to this topic and welcome any idea and proposal. Designing of a PGNAA setup for medical and industrial purposes need time and considering a lot of parameters which is under construction in Ferdowsi University of Mashhad, FUM Radiation Detection and Masurement Lab. For more

Anderson, J., Osborn, S B., Tomlinson, R W S., Newton, D., Rundo, J., Salmon, L., & Smith,

Baur, L A., Allen, B J., Rose, A., Blagojevic, N., & Gaskin, K J. (1991) A total body nitrogen

Beddoe, A H., Zuidmeer, H., & Hill, G L. (1984). A prompt gamma in vivo neutron

Briesmeister, J F. (2000), MCNP A General Monte Carlo N-particle Transport Code, Version

Chichester, D L., & Empey, E. (2004). Measurement of nitrogen in the body using a

Clark M, J., Bartlett, D T., Burgess, P H., Francis, T M., Marshall, T O., & Fry, F A. (1993).

Harvey T C., Dykes P W., Chen N S., Ettinger K V., Jain S., James H., Chettle D R., &

Cohn, S H., Cinque, T J., Dombrowski, C S., & Letteri J M. (1972), *J. Lab. Clin. Med*. Vol. 7,

ICRP 60. (1991). Recommendations of the International Commission on Radiological

Oxford. ICRP (2005) recommendations of the International Commission on Radiological

Mernagh, J R., Harrison, J E., & McNeill, K G. (1977). In vivo determination of nitrogen

Mernagh, J., Harrison, E., & McXeill, K. G. (1977). In vivo Determination of Nitrogen using

Metwally, W M., & Gardner, R P. (2004). Stabilization of prompt gamma-ray neutron

Miri Hakimabad, H., Panjeh, H. & Vejdani, A. R. (2007). Evaluation the nonlinear response

activation analysis (PGNAA) spectra from NaI detectors. *Nucl. Instr. and Meth. A*,

function of a NaI Scintillation detector for PGNAA applications. Appl. Radiat. Isot.

using Pu-Be sources *Phys. Med. Biol.* Vol. 22, pp. 831–5

*Applied Radiation and Isotopes* Vol. 65, pp. 918–926.

Pu-Be Sources. *Phys. Med. Biol.*, Vol. 22, No. 5, pp.831-835.

Mcneill, K. G. (1973). *J. Nucl. Engng*, Vol. 14, No. 3, PP. 84-86.

activation analysis facility formeasurement of total body nitrogen in the critically ill

commercial PGNAA system—phantom experiments. *Appl. Radiat. Isot.* Vol. 60, pp.

Dose quantities for protection against external radiation. *Documents of the NRPB*

Protection, International Commission on Radiological Protection, Pergamon Press,

Protection. Pergamon Press, Oxford. ICRP 103. (2008). Recommendations of the ICRP, International Commission on Radiological Protection, Pergamon Press,

facility for paediatric use *Phys. Med. Biol*.Vol. 36, pp. 1363–1375.

information please don't hesitate to contact me (panjeh@gmail.com).

Alpen, E L. (1998). *Radiation Biophysics 2nd edition*. (Academic Press).

4C, Los Alamos National laboratory, LA–13709–M.

J W. (1964), *Lancet*, Vol. 2, pp. 1201-1205.

*Phys. Med. Biol.* Vol. 29, pp. 373–83.

Vol. 4, pp. 3. (NRPB: Chilton).

Fremlin J H., (1973), *Lancet*, Vol. 2, pp. 395.

**11. Future works** 

**12. References** 

55-61.

pp. 978.

Oxford.

Vol. 525, 518-521.

Fig. 6. A unique design of Body Chemical Composition Analyzer

Fig. 7. Design and Geometry of a Body Chemical Composition Analyzer.

#### **11. Future works**

322 Radioisotopes – Applications in Physical Sciences

Fig. 6. A unique design of Body Chemical Composition Analyzer

Fig. 7. Design and Geometry of a Body Chemical Composition Analyzer.

The authors are attempting to investigate all the aspects related to this topic and welcome any idea and proposal. Designing of a PGNAA setup for medical and industrial purposes need time and considering a lot of parameters which is under construction in Ferdowsi University of Mashhad, FUM Radiation Detection and Masurement Lab. For more information please don't hesitate to contact me (panjeh@gmail.com).

#### **12. References**

Alpen, E L. (1998). *Radiation Biophysics 2nd edition*. (Academic Press).


**16** 

*China* 

**Transportation Pathway of Potassium and** 

*Institute of Horticultural Plants, China Agriculture University, Beijing,* 

Zhenming Niu, Yi Wang, Yanqing Lu, Xuefeng Xu and Zhenhai Han

Since the balance proportion of mineral elements affects the fruit quality, reasonable fertilization is an important way to increase fruit yield and quality. With regard to N, P and K elements, K element is the largest element required by the grape. Various studies have shown that phosphorus and potassium affect the appearance of the fruit quality due to that potassium element could increase the size of grape, citrus and peach fruit, extending the shelf-life, Increasing hardness, beautiful color, and effective anti-browning (Cummings, 1980) simultaneously. P and K elements have an important role in the formation of intrinsic quality of the fruits, for instance, the soluble solid concentration in the apple fruits is in positive correlation with the potassium concentration (Tagliavini et al, 2000). Organic acid content in peach fruit is affected by the nutrition conditions of potassium and nitrogen elements, since potassium could stimulate the accumulation of acid in the fruit, while neutralizing the fruit acidity in part (Habib et al, 2000). Over the annual growth cycle of grapes, whether single application of P and K-fertilization or in coordination with nitrogen fertilizer, spraying on the surface of leaves could obtain different levels of production increase and quality improvement, As a consequence, controlling nitrogen, increasing phosphate and necessary potassium prior to the development and ripening of grapes are the essential measures to obtain superior quality grapes. However, the actual situation in China is attaching great importance on nitrogen while neglecting the application of potassium and phosphorus.which has seriously impacted the grape quality. Therefore, the rational

application of P and K-fertilization has great significance in the grape production.

Ascertaining the effects of mineral elements on fruit quality, and the features of absorption, transportation, distribution of mineral elements are the premise of rational fertilization. Some scientists have applied isotope tracer technique to research the nutrient uptake and distribution, which shows that fruit is one of the centers for nutrient distribution (Hu Shi Bi et al, 1998; Huang Weidong et al, 2002; Xie Shenxi and Zhang Qiuming, 1994). Hu Shi Bi et al (1998) found that soil-applied 86Rb before bloom of grape, the distribution rate at its stems, shoot tips, and leaves at the earlier stage was higher than the inflorescence; foliar application of 86Rb at the same time, the absorption of 86Rb by inflorescence was significantly higher than that of the soil application of 86Rb; foliar 86Rb application at full bloom, the largest distribution was found at the side tip and inflorescence; additionally, the absorption of 86Rb in fruit at ripening period was significantly reduced compared with the previous

**1. Introduction** 

**Phosphorous in Grape Fruit** 

