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From: Anna Ferrari <a.ferrari_at_hzdr.de>

Date: Mon, 09 May 2016 01:33:33 +0200

Dear Yang Tao,

sure that in a shielding problem you have to study also the secondaries...

no doubt about it (in some cases you can conclude that it's enough to

optimize the shielding only for the primary radiation, but this depends on

the problem and on the requirements you have).

The point here is that if you want to check your simulation with the tables

of the mass attenuation coefficients (which represent the photon interaction

probability, and then describe the attenuation of primary photons), then

you have to consider the primaries in the scoring, as pointed out by

Mikhail.

Best,

Anna

Am Fri, 6 May 2016 21:01:19 +0800 (GMT+08:00) schrieb "YANG Tao"

<yangt_at_ihep.ac.cn>:

*> Dear Mikhail!
*

*> Thanks for your detailed reply. I still don't understand why it only scores
*

*>the primary photon, in reality, for the lead shielding effect problems, don't
*

*>we consider the attenuation of all photons(primary + scattered)? Don't the
*

*>scattered photons out of the lead block still need to be shielded?
*

*>
*

*>
*

*> -----原始邮件-----
*

*> 发件人: "Mikhail Polkovnikov <Михаил Полковников>" <pmk_at_ihep.ru>
*

*> 发送时间: 2016年5月6日 星期五
*

*> 收件人: fluka-discuss_at_fluka.org, "YANG Tao" <yangt_at_ihep.ac.cn>
*

*> 抄送:
*

*> 主题: Re: [fluka-discuss]: γ ray count problem using USRBDX
*

*>
*

*>
*

*> On 06.05.2016 12:32, YANG Tao wrote:
*

*>
*

*> Dear Mikhail!
*

*>
*

*>
*

*> Thanks a lot for your reply! It may be the problem of the FLAIR software in
*

*>my computer, I got the correct result in the server. But I have some other
*

*>problems as follows:
*

*>
*

*>
*

*> 1. What's the difference of BEAMPART and PHOTON in my input file? The
*

*>BEAMPART is indeed photon in my input, so the two settings are both correct,
*

*>do you think so?
*

*>
*

*>
*

*> 2. You set the fluence scoring instead of current scoring in the USRBDX
*

*>card, Why do you set as this form, in my opinion, the COUNT of the photon
*

*>number should be one-way current scoring. Besides, the output photon
*

*>number is not the same for the two different setting of the USRBDX card.
*

*>However, in formula calculations the results I/I0 should be 2.1E-4 and your
*

*>input file gets the correct result(about 2.0E-4 _at_primary number is 1000), and
*

*>the one-way current setting in USRBDX gets a much bigger result (~1.0E-3).
*

*>
*

*> Could you solve the puzzles for me?
*

*>
*

*>
*

*> All the best!
*

*>
*

*>
*

*> Tao Yang
*

*>
*

*>
*

*> -----原始邮件-----
*

*> 发件人: "Mikhail Polkovnikov <Михаил Полковников>" <pmk_at_ihep.ru>
*

*> 发送时间: 2016年5月6日 星期五
*

*> 收件人: "YANG Tao" <yangt_at_ihep.ac.cn>, fluka-discuss_at_fluka.org
*

*> 抄送:
*

*> 主题: Re: [fluka-discuss]: γ ray count problem using USRBDX
*

*>
*

*>
*

*> On 06.05.2016 04:21, YANG Tao wrote:
*

*>
*

*> Hello, everyone!
*

*>
*

*>
*

*> I simulate the lead shielding effect for γ ray recently, but I got a strange
*

*>result. Beam position is at (0,0,0) and the beam direction is in z-direction.
*

*>The gamma rays were directed towards a simple cuboid lead block with 10.5 cm
*

*>in thickness and 200cm*200cm in length and width. USRBDX score card has been
*

*>used to obtain the transmission values, I/I0, where I0 and I are the incident
*

*>and attenuated photon intensities. Theoretically, I0 is 1 photon/primary
*

*>since the incident photon will all penetrate the front surface of the lead
*

*>block, however, the result (31BIN, "rushe") always give ZERO result, it's
*

*>confusing, where did the photons go? Additionly, the exit photon (32BIN,
*

*>"chushe") also give a wrong results compared to other literature.
*

*> These problems have confused me for several days, so any help will be
*

*>appreciated much!!!
*

*>
*

*> Thank You!
*

*>
*

*> Tao Yang
*

*>
*

*> CAS
*

*>
*

*>
*

*> Dear Tao Yang,
*

*>
*

*> If you are interested only in attenuation of primary photons, you can try
*

*>these two USRBDX's:
*

*>
*

*> *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....
*

*> USRBDX 109. BEAMPART 21. valeft qiankuai 1.in
*

*>
*

*> USRBDX 1.0E-3 8.0E-4 1. 1. &
*

*>
*

*>
*

*> *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....
*

*> USRBDX 109. BEAMPART 21. qiankuai varigh 1.out
*

*>
*

*> USRBDX 1.0E-3 8.0E-4 1. 1. &
*

*>
*

*>
*

*> In - input fluence before lead block
*

*>
*

*> out - output fluence after lead block
*

*>
*

*> The value (out / in) is close to the formula calculations ( mu = 0.07102
*

*>cm^2/g, density = 11,35 g/cm^3)
*

*>
*

*>
*

*> Best regards,
*

*>
*

*> Mikhail
*

*>
*

*>
*

*> --
*

*>
*

*>
*

*> 杨涛
*

*> 中科院高能所东莞分部（东莞中子科学中心）加速器技术部
*

*> 地址：东莞市大朗镇中子源路1号中国散裂中子源A2栋606室
*

*> E-mail：yangt_at_ihep.ac.cn
*

*> 电话：0769-38944239
*

*> 邮编：523803
*

*>
*

*>
*

*> Dear Tao Yang,
*

*>
*

*>
*

*> 1. In your case BEAMPART are only primary photons from the source, PHOTON
*

*>are all photons (primary + scattered). That is why the result with
*

*>part=PHOTON in your USRBDX is bigger.
*

*> 2. You can set one-way current scoring and the result will be basically the
*

*>same for BEAMPART photons.
*

*>
*

*> Best regards,
*

*> Mikhail
*

*>
*

*> --
*

*>
*

*>
*

*> 杨涛
*

*> 中科院高能所东莞分部（东莞中子科学中心）加速器技术部
*

*> 地址：东莞市大朗镇中子源路1号中国散裂中子源A2栋606室
*

*> E-mail：yangt_at_ihep.ac.cn
*

*> 电话：0769-38944239
*

*> 邮编：523803
*

*>
*

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dr. Anna Ferrari

Institute of Radiation Physics

Helmholtz-Zentrum Dresden-Rossendorf e.V.

Tel. +49 351 260 2872

a.ferrari_at_hzdr.de

http://www.hzdr.de

Vorstand: Prof. Dr. Dr. h. c. Roland Sauerbrey, Prof. Dr. Dr. h. c. Peter

Joehnk

Vereinsregister: VR 1693 beim Amtsgericht Dresden

__________________________________________________________________________

You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info

Received on Mon May 09 2016 - 03:18:42 CEST

Date: Mon, 09 May 2016 01:33:33 +0200

Dear Yang Tao,

sure that in a shielding problem you have to study also the secondaries...

no doubt about it (in some cases you can conclude that it's enough to

optimize the shielding only for the primary radiation, but this depends on

the problem and on the requirements you have).

The point here is that if you want to check your simulation with the tables

of the mass attenuation coefficients (which represent the photon interaction

probability, and then describe the attenuation of primary photons), then

you have to consider the primaries in the scoring, as pointed out by

Mikhail.

Best,

Anna

Am Fri, 6 May 2016 21:01:19 +0800 (GMT+08:00) schrieb "YANG Tao"

<yangt_at_ihep.ac.cn>:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dr. Anna Ferrari

Institute of Radiation Physics

Helmholtz-Zentrum Dresden-Rossendorf e.V.

Tel. +49 351 260 2872

a.ferrari_at_hzdr.de

http://www.hzdr.de

Vorstand: Prof. Dr. Dr. h. c. Roland Sauerbrey, Prof. Dr. Dr. h. c. Peter

Joehnk

Vereinsregister: VR 1693 beim Amtsgericht Dresden

__________________________________________________________________________

You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info

Received on Mon May 09 2016 - 03:18:42 CEST

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